How Reddit Citations Changed in Gemini for High-Stakes Health and Medical Consumer Decisions

LLM Authority Index Research | High-Stakes Consumer Decisions | Health and Medical | Gemini | July-September 2026

Reddit's direct citation visibility in Gemini weakened across the strict matched health and medical panel from July to September 2026, but the change occurred from a low baseline and with small absolute counts.

Across 144 exact prompt-plus-Gemini scenarios observed at both endpoints, Reddit recorded 5 losses and 3 gains.

No matched scenario cited Reddit at both endpoints.

Matched Reddit response coverage therefore fell from 3.47% in July to 2.08% in September, a 40.0% relative decline.

The loss-to-gain ratio was 1.67 to 1.

Using the published 5-loss, 3-gain contingency table, the derived exact two-sided McNemar result is p = 0.7265625.

That is not statistically significant at a conventional 0.05 threshold.

The result should therefore be interpreted as directionally negative but statistically weak on its own.

The broader three-month Gemini health source market also shows that Reddit was never a dominant source in this category.

Across 1,819 eligible deduplicated Gemini health responses, Reddit appeared in 17 responses, or 0.93%, and generated 17 of 3,155 substantive public-facing citation events, approximately 0.54% of the cleaned citation pool.

Reddit ranked #35 overall across the three-month Gemini health and medical source market.

Its monthly rank moved from #23 in July to #43 in August and #48 in September.

That pattern is materially different from ChatGPT and Perplexity, where Reddit occupied a much more prominent health citation position earlier in the quarter.

Important: The parent Health and Medical Reddit study publishes Gemini-specific matched counts and matched response coverage, but it does not publish a separate Gemini-wide balanced July-to-September aggregate citation-event share or response-coverage table. This article therefore does not invent a Gemini aggregate endpoint percentage. It uses the published matched panel for longitudinal endpoint analysis and the published three-month Gemini source study for quarter-wide context.

Answer Capsule

Did Reddit citation visibility decline in Gemini for high-stakes health and medical decisions from July to September 2026? Yes in the strict matched panel, but from a low baseline. Across 144 exact prompt-plus-Gemini scenarios, Reddit recorded 5 losses and 3 gains, reducing matched response coverage from 3.47% to 2.08%, a 40.0% relative decline. The derived exact McNemar result is p = 0.7265625, so the matched imbalance is not statistically significant. Across the full three-month Gemini health source market, Reddit ranked #35, appearing in 17 of 1,819 responses, or 0.93%.

Key Findings

• The strict matched Gemini health panel contained 144 exact prompt-plus-platform scenarios.
• Reddit recorded 5 matched losses and 3 gains.
• There were 0 persistent Reddit citations across the matched endpoints.
• Matched Reddit response coverage fell from 3.47% to 2.08%.
• Matched relative decline: 40.0%.
• Loss-to-gain ratio: 1.67 to 1.
• Derived exact two-sided McNemar result: p = 0.7265625.
• The matched result is directionally negative but not statistically significant.
• Across the full three-month Gemini health source market, Reddit appeared in 17 of 1,819 responses, or 0.93%.
• Reddit generated 17 of 3,155 substantive citation events, approximately 0.54%.
• Reddit ranked #35 overall.
• Reddit's monthly rank moved #23 in July, #43 in August and #48 in September.
• Reddit appeared across 5 of the 14 health and medical source labels.
• Gemini's health source market contained 743 registrable cited domains and 3,026 domain-response appearances.
• 213 technical or unusable citation entries were excluded from the public publisher ranking.
• GoodRx ranked #1 at 6.21% response coverage, followed by Healthline 5.66%, Forbes 5.61%, NCOA.org 5.39%, and SeniorLiving.org 5.11%.
• Only 31 of the health Top 100 domains also appeared in Gemini's broader High-Stakes Consumer Decisions Top 100.
• Reddit's health visibility was much lower in Gemini than in ChatGPT, Perplexity or Google's AI search surfaces.
• The parent health study does not publish a separate Gemini balanced aggregate endpoint share, so this child article does not manufacture one.

Questions This Study Answers

• Did the same Gemini health prompts lose Reddit more often than they gained it?
• How important was Reddit in Gemini's three-month health source market?
• Why can broad Gemini source studies show Reddit as important while this health-specific panel ranks it only #35?

Why This Research Belongs in Daily AI Search Marketing Decisions

Article 65 isolates one source, Reddit, inside one platform, Gemini, and one commercial decision family, Health and Medical. Its operating value comes from separating a low-frequency matched decline from the structure and turnover of the surrounding Gemini Health source market.

1. How important was Reddit across the full three-month Gemini Health source market?
2. Did the exact same prompts lose Reddit more often than they gained it?
3. How should marketers interpret the result when the matched imbalance is not statistically significant?

Across the full three-month Gemini Health and Medical source study, Reddit ranked #35 overall at 0.93% response citation coverage. It appeared in 17 of 1,819 eligible responses and generated 17 of 3,155 substantive public-facing citation events, about 0.54% of the cleaned event pool.

Its monthly rank moved steadily lower: #23 in July, #43 in August and #48 in September.

The strict matched panel points in the same direction, but from a small base. Across 144 exact prompt-plus-Gemini scenarios, Reddit produced 5 losses, 3 gains, 0 persistent citations and 136 neither-month scenarios. Matched response coverage fell from 3.47% to 2.08%, a 40.0% relative decline, and the loss-to-gain ratio was 1.67 to 1.

The derived exact two-sided McNemar result is p = 0.7265625. That is not statistically significant at a conventional 0.05 threshold. The defensible conclusion is therefore low-frequency deterioration with a directionally negative but statistically weak matched signal, not a confirmed platform-wide collapse.

Article 65 does not publish a separate Gemini-specific balanced aggregate July-to-September citation-event share or response-coverage percentage because the frozen parent Health study does not publish those values. The longitudinal claim is based on the published matched panel, while the quarter-wide context comes from the three-month Gemini Health source study.

For publishers, large percentage changes from tiny raw counts should always be paired with the underlying counts. For healthcare brands, providers, medical-device companies, senior-care businesses and CMOs, Gemini should be measured as its own source environment rather than blended with Google AI Overviews, Google AI Mode, ChatGPT, Perplexity or Copilot.

The surrounding Gemini Health source market is relatively diffuse and only moderately persistent. The Top 10 account for 24.72% of domain-response appearances, while the Top 100 account for 63.95%. Only 45 domains remained in the monthly Top 100 across July, August and September, and median monthly Top 100 Jaccard similarity was 39.9%.

Category specialization is substantial. Only 31 of Gemini's Health and Medical Top 100 domains also appear in Gemini's broader High-Stakes Consumer Decisions Top 100, an 18.3% Jaccard similarity. The final Health child-study Top 100 lists show Gemini sharing 54 domains with Google AI Mode, 52 with Google AI Overviews, 46 with Perplexity, 39 with ChatGPT and 33 with Microsoft Copilot.

The broader Health and Medical Citation Authority Study reports 61.3% median monthly Top 100 persistence, 25.8% median cross-platform Top 100 portability, and an approximate 35.5 percentage-point Persistence-Portability Gap. The final six Health platform studies contain 290 distinct Top 100 domains in their union. Only 20 domains appear in all six platform Top 100s, while 161 appear in only one.

The Persistence-Portability Gap framework helps interpret Article 65 correctly. Health source authority is more persistent over time than universally portable across engines, while Gemini's own Health source market rotates more quickly. Article 65 should not create a Gemini-specific gap by subtracting 39.9% temporal persistence from one pairwise platform overlap because those comparison structures are different.

The parent Health and Medical Reddit decline study provides broader family context. Across the balanced all-platform Health family, Reddit citation-event share fell from 2.13% to 0.99%, down 53.5%, while response citation coverage fell from about 6.91% to 3.63%, down about 47.5%. Thirteen health verticals had both endpoint datasets, ten had measurable July Reddit event share, and all 10 of those 10 declined. Those are family-level results, not Gemini-specific balanced endpoint metrics.

Gemini also requires source-surface cleanup. The source study excludes 213 technical or unusable entries from the public publisher ranking: 69 myactivity.google.com account-activity entries and 144 citation records without a usable URL.

Citation visibility should remain separate from brand mentions, recommendation rate, rank, sentiment, citation-recommendation coupling, clinical quality, treatment safety and downstream business outcomes. A visible citation does not prove that a source caused Gemini to recommend a provider, product, clinic or treatment, and citation frequency is not a medical-quality score.

Commercial Action Matrix: What Publishers and CMOs Can Do With the Findings

Need company- or vertical-specific tracking? Publishers and companies can contact LLM Authority Index for individual vertical research, recurring AI citation tracking and company-level reporting. The research service does not sell rankings, inclusion or recommendation placement.

Where Article 65 Fits in the High-Stakes Consumer Decisions Corpus

Article 65 is a child analysis of two parent studies:

• the Health and Medical Reddit decline study, which provides the balanced family context, platform-specific matched comparison and broader replacement analysis; and
• the Gemini Health and Medical source study, which provides the surrounding three-month source market, including Reddit's #35 aggregate rank and 0.93% response coverage, 45 domains present in all three monthly Top 100s and 39.9% median monthly Top 100 persistence.

The platform-level context comes from the overall Gemini Top 100 study. The broader interpretation comes from the 2026 AI Citation Authority Study, the overall Reddit decline study, the cross-platform citation-overlap study, the citation-drift study, and the Persistence-Portability Gap framework. Those studies answer different questions and should not be collapsed into one visibility score.

The Core Matched Finding: Five Losses and Three Gains

Questions This Section Answers

• What happened when the exact prompt and Gemini platform were held constant?
• How much did matched Reddit coverage change?
• Was the loss-gain imbalance statistically significant?

The strict matched panel controls for prompt identity and platform.

A scenario qualifies only when the same normalized prompt on the same Gemini platform family has one eligible analytical observation in July and one in September.

144 scenarios met that contract.

Matched Reddit response coverage moved from:

5 / 144 = 3.47%

to:

3 / 144 = 2.08%

That is a 40.0% relative decline.

The loss-to-gain ratio is 1.67 to 1.

For the eight discordant pairs, the derived exact two-sided McNemar p-value is 0.7265625.

The matched evidence therefore leans negative but is not statistically significant.

The raw counts matter more than the relative percentage alone.

A 40% decline sounds large, but it is produced by a change from five July-positive matched scenarios to three September-positive matched scenarios.

Why This Article Does Not Publish a Separate Gemini Aggregate Endpoint Percentage

Questions This Section Answers

• Why is there no Gemini-specific balanced July-to-September event-share table here?
• Is that metric unavailable or intentionally omitted?
• Which evidence is used instead?

The parent Health and Medical Reddit study publishes:

• the balanced all-platform family endpoint;
• platform-specific matched counts and matched coverage;
• the all-platform replacement analysis; and
• the cross-platform matched comparison.

It does not publish separate Gemini aggregate July and September citation-event shares or response citation coverage rates.

The supporting Gemini source study publishes:

• three-month response coverage;
• three-month citation-event counts;
• three-month rank;
• monthly rank;
• monthly Top 100 overlap;
• category lift; and
• source-market totals.

It does not publish month-specific Reddit response counts or month-specific Reddit citation-event counts.

This article therefore uses the 144-scenario matched panel for Gemini longitudinal change and the 1,819-response three-month source study for market context.

It does not infer a Gemini aggregate endpoint percentage from monthly rank.

Reddit Ranked #35 Across the Three-Month Gemini Health Market

Questions This Section Answers

• Was Reddit a major Gemini health source across the quarter?
• What was Reddit's three-month response coverage?
• How did Reddit compare with the category leaders?

Across the full three-month Gemini health source market:

Reddit was therefore present, but at a much lower frequency than Gemini's leading health sources.

The top five were:

GoodRx appeared in 113 responses.

Reddit appeared in 17.

That difference helps explain why a small number of Reddit gains or losses can produce large relative percentage changes without materially reshaping Gemini's overall health source hierarchy.

Reddit's Monthly Rank Drifted Downward

Questions This Section Answers

• Did Reddit's Gemini health rank move in the same direction as the matched panel?
• How much did monthly rank change?
• Was the decline abrupt or gradual?

Reddit's monthly source-market rank moved:

The pattern is a steady rank decline across the three months.

That is directionally consistent with the matched panel's five losses against three gains.

But monthly rank and matched response coverage are different metrics.

Monthly rank reflects Reddit's position relative to every other cited domain that month.

Matched coverage isolates source persistence on exact repeated prompt-platform scenarios.

Both point toward weaker Reddit visibility, but neither should be substituted for the other.

Gemini's Leading Health Sources Were More Persistent Than Reddit

Questions This Section Answers

• Which sources stayed near the top across all three months?
• Was Reddit's movement unusual relative to category leaders?
• Which source held the most stable top-tier position?

Gemini's leading health sources showed much stronger persistence.

Examples:

• GoodRx: #1 → #3 → #2
• Healthline: #3 → #4 → #1
• Forbes: #2 → #5 → #5
• NCOA.org: #4 → #2 → #4
• SeniorLiving.org: #12 → #1 → #3
• Reddit: #23 → #43 → #48

The monthly #1 source changed, but the leading health-specialist and large publisher group remained clustered near the top.

Reddit moved in the opposite direction and from a much lower starting position.

Gemini's Health Source Market Was Highly Category-Specific

Questions This Section Answers

• How much did Gemini health overlap with Gemini overall?
• Would a broad Gemini source list capture the right healthcare publishers?
• Why does health-specific source mapping matter?

Only 31 of the health and medical Top 100 domains also appeared in Gemini's broader High-Stakes Consumer Decisions Top 100.

That produces a Jaccard similarity of approximately 18.3%.

This is a strong category effect.

Broad Gemini source authority does not automatically translate into high-stakes health authority.

Health prompts elevate sources such as:

• GoodRx
• NCOA.org
• SeniorLiving.org
• HelpGuide.org
• Doctor on Demand
• ElderLife Financial
• Doctronic
• HearingTracker
• specialty testing and care providers

A broad source leaderboard can therefore miss much of the category-specific ecosystem.

Specialist Health Sources Over-Indexed Sharply

Questions This Section Answers

• Which health sources had unusual strength inside Gemini's health panel?
• Did specialist sources compete effectively with large publishers?
• What does that mean for healthcare visibility strategy?

The supporting Gemini source study notes that GoodRx, Healthline, NCOA.org and HelpGuide all have substantially higher response coverage inside the health-focused slice than across Gemini's broader high-stakes corpus.

Product-level leadership also varies.

Examples from the source study include specialist and provider-owned domains becoming important in:

• hearing aids;
• medical alert systems;
• online doctors;
• online pharmacies;
• online therapy;
• fertility and IVF;
• STD testing; and
• metabolic-health services.

The source market is therefore not one generic list of large websites.

It is a mix of broad publishers, specialist health information sources, consumer-service sites and provider-owned properties.

Gemini's Technical Citation Layer Required Meaningful Cleanup

Questions This Section Answers

• How many citation records were excluded from the public ranking?
• Which technical entries were removed?
• Does cleanup materially affect the denominator?

The deduplicated Gemini health slice contained 3,368 captured citation entries before public filtering.

The source study removed:

That leaves 3,155 substantive public-facing citation events.

The public publisher ranking therefore excludes account-activity infrastructure and unusable source records rather than treating them as editorial sources.

Reddit's 17 citation events are measured against this cleaned substantive denominator.

Gemini's Matched Reddit Pattern Was Mild Compared With ChatGPT

Questions This Section Answers

• How did Gemini compare with the other health platforms?
• Which platform had the strongest Reddit break?
• Why is a single cross-platform Reddit KPI misleading?

The parent Health and Medical study reports:

Gemini's result is negative, but far less extreme than ChatGPT.

ChatGPT recorded 30 losses and no gains.

Gemini recorded five losses and three gains.

Perplexity reached zero matched September coverage, but from only three July-positive scenarios.

Google's AI surfaces retained more Reddit continuity.

Copilot had no matched Reddit baseline at either endpoint.

The platforms are clearly not interchangeable.

The Parent Health Family Declined More Than Half in Citation-Event Share

Questions This Section Answers

• Was Gemini part of a broader health-family decline?
• How large was the overall health decline?
• How broad was the decline by vertical?

Across the balanced all-platform Health and Medical family, Reddit citation-event share fell from 2.13% to 0.99%, a 53.5% relative decline.

Response citation coverage fell from approximately 6.91% to 3.63%, down about 47.5%.

Thirteen health and medical verticals had both July and September datasets.

Ten had measurable Reddit citation-event share in July.

All 10 declined by September.

The median decline among those ten measurable verticals was 44.5%.

Those are family-wide results, not Gemini-specific aggregate endpoint rates.

This article preserves that distinction.

No Single Source Replaced Reddit Across the Parent Health Study

Questions This Section Answers

• Did one publisher consistently replace Reddit?
• Which sources most often appeared after Reddit losses?
• Can those results be attributed specifically to Gemini?

The parent health study examined 85 matched Reddit-loss scenarios across all tracked platforms.

The most common newly appearing domains were:

No source consistently replaced Reddit.

These are all-platform health-family results, not a Gemini-only replacement table.

The Gemini-specific matched evidence is limited to five losses, three gains and zero persistent citations.

Which Health and Medical Verticals Are Represented?

The full Gemini health source study contains 14 source labels:

1. Addiction Treatment Centers
2. Assisted Living Facilities
3. Dental Implants
4. Fertility Clinics
5. Hearing Aids
6. Home Health Care
7. IVF Clinics
8. Medical Alert Systems
9. Mental Health Treatment Centers
10. Online Doctors
11. Online Pharmacies
12. Online Therapy
13. STD Tests
14. Weight Loss and Metabolic Health

Medical Alert Systems has no July source file in the frozen archive.

The parent balanced July-to-September health-family endpoint therefore uses 13 comparable verticals.

The three-month Gemini source ranking includes all 14 labels.

Reddit appears across 5 of them.

How This Study Relates to Prior Gemini and Health Citation Research

Questions This Section Answers

• How can broad Gemini research rank Reddit #1 while this Health panel ranks it #35?
• What does broader Q3 research say about social citation behavior across AI platforms?
• What does independent healthcare citation research say about engine-specific source hierarchies?

Ahrefs' September 2026 Gemini study ranks Reddit #1 at 28.5% mention share across more than 3 million U.S. queries spanning all topics. Article 65 instead ranks Reddit #35 at 0.93% response citation coverage across a three-month high-stakes Health and Medical panel.

Those findings are not contradictory. Ahrefs measures a broad all-topic U.S. query universe and defines mention share as a domain's share of citations among its top sources. Article 65 measures response citation coverage and citation-event share inside one commercial decision family. Broad Gemini prominence for Reddit therefore does not imply high Reddit visibility inside Health and Medical buyer journeys.

Tinuiti's Q3 2026 AI Citation Trends Report says most tracked AI platforms were at or near Q3 highs in social citation share, with Perplexity as the notable exception. Tinuiti tracks a different mix of categories, including OTC health, and reports broader social-source behavior rather than Reddit-only Health citations. Its findings should therefore be used as platform context, not merged numerically with Article 65.

BrightEdge's August 2026 healthcare citation research also shows that source hierarchies can differ sharply by engine inside sensitive categories. In its tracked healthcare prompts, ChatGPT's top five sources were government agencies or hospital systems, while Google AI Overviews showed much stronger YouTube visibility. BrightEdge measures different engines and a different healthcare prompt population, but the operational lesson is directly relevant: health authority is engine-specific and category-specific.

Taken together, the outside research strengthens the case for measurement discipline rather than a universal Reddit narrative. The defensible comparison is platform, category, time period, query population and metric, not decimal-point equivalence across unrelated panels.

How This Study Relates to the Parent Health Reddit Study

The parent Health and Medical study found that Reddit's balanced all-platform citation-event share fell from 2.13% to 0.99%, a 53.5% relative decline.

Balanced response citation coverage fell from approximately 6.91% to 3.63%, down about 47.5%.

Across the all-platform strict matched panel, Reddit losses outnumbered gains 85 to 32.

Gemini contributed:

• 5 losses
• 3 gains
• 0 persistent citations
• 136 neither-month scenarios

That produces a Gemini matched coverage move from 3.47% to 2.08%.

This child analysis adds Gemini-specific three-month source-market context without misrepresenting the all-platform family decline as a Gemini aggregate endpoint statistic.

How This Study Is Different

This article narrows the broader health Reddit research to one platform, one high-stakes family and one three-month research period.

It combines:

1. a 144-scenario strict matched prompt-plus-Gemini panel;
2. a 1,819-response three-month Gemini Health and Medical source slice;
3. matched endpoint coverage and pooled-quarter source-market coverage;
4. Reddit monthly rank movement from #23 to #43 to #48;
5. a source market containing 743 registrable cited domains;
6. explicit treatment of 213 technical or unusable citation entries;
7. category-overlap analysis showing only 31 shared domains with Gemini's broader Top 100;
8. comparison with broad Gemini research from Ahrefs;
9. comparison with Tinuiti's Q3 platform findings; and
10. explicit disclosure that the frozen parent sources do not publish a separate Gemini balanced aggregate endpoint share.

The narrow research question is:

How stable was Reddit as a directly cited source in Gemini for consequential health and medical consumer decisions from July through September 2026?

Why AI Citation Studies Can Disagree

Questions This Section Answers

• Why can broad Gemini studies show more Reddit prominence than this health panel?
• Why can a three-month rank differ from a matched endpoint result?
• What should healthcare marketers compare before using an external benchmark?

Query population

Broad all-topic Gemini studies include many categories where Reddit may be used more frequently.

Time period

The three-month source ranking pools July, August and September.

The matched test compares July and September only.

Denominator

Response citation coverage, citation-event share, monthly rank and external mention-share metrics answer different questions.

Category specialization

Health prompts elevate specialist sources such as GoodRx, NCOA, Healthline and provider-owned sites.

Low Reddit baseline

Reddit appears in only 17 of 1,819 three-month Gemini health responses.

Small count movement can therefore produce large relative percentages.

Missing July data

Medical Alert Systems does not have a July source dataset and is excluded from the balanced parent endpoint.

Technical-source cleanup

The Gemini health source study excludes 69 myactivity.google.com entries and 144 records without usable URLs.

Prompt matching

The strict paired analysis requires the same normalized prompt and Gemini platform at both endpoints.

Prompt weighting

The panel is not weighted by patient volume, healthcare spend, search volume, CPC, revenue or conversion probability.

The correct question is not:

"What is Reddit's universal Gemini health citation rate?"

The useful question is:

What did Reddit citation visibility look like for this platform, this health decision population, this time period and this measurement definition?

Methodology

Source archive

This study uses the frozen July-September 2026 LLM Authority Index High-Stakes Consumer Decisions corpus underlying the Health and Medical source studies and the parent health Reddit analysis.

Platform filter

Only observations assigned to the Gemini platform family are used for the child platform analyses.

Category filter

Observations are included when their source membership belongs to the Health and Medical family.

Three-month Gemini health source sample

The supporting source study reports:

• 1,985 raw July-September Gemini health observations
• 4 explicit extraction failures
• 1,981 valid observations before exact-repeat handling
• 1,819 eligible deduplicated responses
• 3,368 captured citation entries after exact-repeat handling
• 69 myactivity.google.com technical exclusions
• 144 citation records without a usable URL
• 3,155 substantive public-facing citation events
• 743 registrable cited domains
• 3,026 domain-response appearances

Exact analytical repeat handling

Exact analytical repeats are controlled using the project's documented repeat rules so duplicate observations do not inflate source coverage.

Prompt normalization

Matched prompt text is normalized using Unicode NFKC normalization, case folding, whitespace collapse and trimming.

Domain normalization

Citation URLs are parsed to hostname, lowercased, stripped of leading www where applicable and consolidated to registrable domain using Public Suffix List logic.

Reddit identification

Reddit is identified at the registrable-domain level as reddit.com.

Public technical exclusions

The Gemini health public ranking excludes:

• 69 myactivity.google.com entries
• 144 citation records without a usable source URL

Total excluded: 213.

Three-month Reddit response coverage

Reddit response citation coverage = eligible responses citing Reddit at least once / all eligible responses

For the three-month source market:

17 / 1,819 = 0.93%

Three-month Reddit citation-event share

Reddit citation-event share = Reddit citation events / all eligible substantive public citation events

For the three-month source market:

17 / 3,155 ≈ 0.54%

Matched prompt-plus-platform test

The strict matched Gemini panel contains 144 scenarios.

The contingency table is:

• both July and September cite Reddit: 0
• July cites Reddit, September does not: 5
• July does not cite Reddit, September cites Reddit: 3
• neither month cites Reddit: 136

Matched response coverage falls from:

5 / 144 = 3.4722%

to:

3 / 144 = 2.0833%

Relative change: -40.0%.

The exact two-sided McNemar p-value derived from the published contingency table is 0.7265625.

Aggregate endpoint availability

The frozen parent study does not publish separate Gemini-specific balanced aggregate July and September citation-event share or response-coverage values.

Those values are therefore left unpublished rather than inferred.

Limitations

1. The strict matched Gemini panel contains only eight discordant Reddit scenarios.
2. The derived exact McNemar p-value does not cross a conventional 0.05 significance threshold.
3. The parent source does not publish a separate Gemini aggregate balanced endpoint share.
4. Reddit's three-month Gemini health baseline is low at 0.93% response coverage.
5. The three-month source ranking pools July, August and September and should not be treated as a September-only rate.
6. Visible citation does not prove recommendation causality, hidden retrieval influence or training-data use.
7. Medical Alert Systems does not have a July source file and is excluded from the balanced parent endpoint.
8. Domain-level aggregation hides page-level source differences.
9. Technical-source cleanup can make denominators differ from raw citation exports.
10. Gemini behavior can vary by geography, personalization, account state, model version, retrieval configuration and product rollout.
11. The all-platform replacement table should not be interpreted as a Gemini-only replacement analysis.
12. The study does not evaluate the medical quality or clinical reliability of Reddit content.

Commercial Disclosure

LLM Authority Index is affiliated with CiteWorks Studio and related AI-search research and services. This research documents observed AI citation behavior.

Commercial relationships do not alter the frozen source corpus, platform filter, category filter, matching contract or published denominators.

No company can purchase a ranking, recommendation, score or position in this study. Citation visibility should not be interpreted as an endorsement by LLM Authority Index or Google Gemini.

References

1. LLM Authority Index: The 2026 AI Citation Authority Study
2. LLM Authority Index: The Most-Cited Websites in AI for High-Stakes Health and Medical Consumer Decisions
3. LLM Authority Index: Reddit's Decline in AI Citations for High-Stakes Health and Medical Consumer Decisions
4. LLM Authority Index: The 100 Most-Cited Websites in Gemini for High-Stakes Health and Medical Consumer Decisions
5. LLM Authority Index: The Persistence-Portability Gap
6. LLM Authority Index: The 100 Most-Cited Websites in Gemini for High-Stakes Consumer Decisions
7. Ahrefs: The 50 Most-Cited Websites in Gemini, September 2026
8. Tinuiti: Q3 2026 AI Citation Trends Report
9. BrightEdge: Health and Finance Citation Authority Across ChatGPT and Google AI Overviews

Related LLM Authority Index Research

Corpus foundation and measurement framework

• 2026 AI Citation Authority Study
• Overall Reddit Citation Decline Study
• Cross-Platform Citation Overlap Study
• AI Citation Drift Study
• Overall Gemini Top 100 Study
• Persistence-Portability Gap Framework

Health and Medical source-market branch

• All-Platform Health and Medical Citation Authority Study
• Google AI Overviews Health and Medical Citation Sources
• Google AI Mode Health and Medical Citation Sources
• ChatGPT Health and Medical Citation Sources
• Perplexity Health and Medical Citation Sources
• Gemini Health and Medical Citation Sources
• Microsoft Copilot Health and Medical Citation Sources

Health and Medical Reddit-trend branch

• Health and Medical Reddit Decline Parent Study
• Google AI Overviews Reddit Trend
• Google AI Mode Reddit Trend
• ChatGPT Reddit Trend
• Perplexity Reddit Trend
• Gemini Reddit Trend
• Microsoft Copilot Reddit Trend