How AI Search Is Recommending Peptide Suppliers: Monthly Trends

Executive Summary

Phoenix Pharmaceuticals remains the category leader for September 2026 at 18.6% valid recommendation coverage, but the leader's position has narrowed across the three-month series. The gap between first place and second place stood at 10.2 points in July (Phoenix Pharmaceuticals versus Core Peptides), narrowed to 3.6 points in August (Phoenix Pharmaceuticals versus AminoVault, which held second place that month), and now stands at 3.5 points in September (Phoenix Pharmaceuticals versus Core Peptides). The benchmark shows the leader's coverage has declined in each of the three measured months, from 38.3% in July to 23.4% in August to 18.6% in September.

Blue Sky Peptide was the strongest upward mover this month, rising 0.6 points from 4.8% in August to 5.4% in September, a change within normal variation for this period. Across the full three-month series, the brand climbed from 0.4% in July to 5.4% in September, a significant rise of 5.0 points from a small base. The sharpest single-month decline belonged to AminoVault, which fell 8.7 points from 19.8% in August to 11.1% in September, a significant drop that erased most of its prior gain.

Three brands qualified as significant decliners across the full baseline-to-current series: Core Peptides, Biotech Peptides, and Phoenix Pharmaceuticals. Core Peptides fell 13.0 points from 28.1% to 15.1%, Biotech Peptides dropped 9.2 points from 22.3% to 13.1%, and Phoenix Pharmaceuticals declined 19.7 points from 38.3% to 18.6%. The category is in a mixed state, with one significant riser, three significant decliners, and three stable brands.

This benchmark began with 530 prompt-surface observations across 349 unique questions in September 2026 (375 prompt-surface observations across 265 unique questions in July 2026 and 467 across 319 in August). Of the September total, 530 prompts mentioned a tracked brand or competitor, of which 469 were relevant to the category and 61 were irrelevant. The public benchmark is built from the 350 qualified observations that survived both qualification stages in September, up from 274 in July and 334 in August.

Key Findings

Benchmark Context

The report separates the raw collection universe from the qualified analysis set. Brand-level recommendation percentages are calculated within the qualified benchmark set.

Benchmark-Level Metrics

The table below summarizes category-wide totals for the two-month comparison period, separate from the individual brand figures that follow.

The intermediate August figures help interpret the trend: recommendation-shaped answer share moved from 47.1% in July to 47.6% in August, then fell to 27.1% in September. Valid recommendation shortlist share followed a similar path, at 52.2%, 38.9%, then 31.7%. The benchmark's raw collection grew across all three months, meaning the declines in these rates occurred against a larger qualified observation set.

AI Recommendation Trend

Category Leader Retained, Field Compressed

Phoenix Pharmaceuticals holds the top position in September 2026, but the competitive field is the tightest it has been across the three measured months. The leader's 18.6% coverage sits just 3.5 points above Core Peptides at 15.1% and 5.5 points above Biotech Peptides at 13.1%. The mid-tier brands have converged into a narrow band.

The category-level compression reflects the combination of several significant declines rather than a single dominant movement. Three brands moved significantly downward across the series while one moved significantly upward, and the aggregate effect is a field where no brand reaches even one-fifth of qualified observations.

What Changed This Month

Phoenix Pharmaceuticals: Leader Retained with Continued Decline

Phoenix Pharmaceuticals retained the top position for September 2026, but its valid recommendation coverage fell again, down 4.8 points from 23.4% in August to 18.6% in September. This change was within the range of normal month-to-month variation for this period, though across the full series the decline is substantial: the brand fell 19.7 points from 38.3% in July.

The brand's raw presence held essentially stable at 59.7% in September versus 60.8% in August, meaning visibility did not drive the coverage change. Top-three recommendation rate declined 4.7 points from 14.1% to 9.4%, and rank-one recommendations fell 2.5 points to 3.1%, with 11 rank-one placements in 350 September observations versus 19 of 334 in August.

The distinction the reader should notice is that Phoenix Pharmaceuticals remains the most visible brand in the category by a wide margin, but a declining share of answers convert that presence into a valid recommendation. Presence and recommendation continue to move apart.

Highest-priority diagnostic: Which prompt types are no longer returning Phoenix Pharmaceuticals as a top-three or rank-one recommendation, and which competitor is most often named in the answers the brand lost?

AminoVault: Significant Decline from a Peak

AminoVault fell 8.7 points from 19.8% in August to 11.1% in September, a significant decline. Across the full series, the brand's coverage is down only 0.9 points from July's 12.0%, meaning the September figure largely erased the August gain rather than extending a downward trend.

Raw presence reached 19.1% in September, up from 12.4% in July but below August's 21.6%. Top-three rate was 8.3% and rank-one rate 5.7%, each essentially flat against July levels. Valid recommendation count fell from 66 in August to 39 in September, with 20 rank-one placements of 350 observations.

The movement here is a retracement: AminoVault's August surge was not sustained into September. The brand remains present in roughly one in five answers but its recommendation share returned to the level where the series began.

Highest-priority diagnostic: Which surfaces or prompt patterns drove the August rank-one growth, and which of those did not persist into September?

Core Peptides: Significant Decline, Stronger September

Core Peptides fell 13.0 points across the full series, from 28.1% in July to 15.1% in September, a significant decline. The sharpest movement occurred between July and August, when coverage dropped 14.9 points to 13.2%. Between August and September, the brand recovered 1.9 points to 15.1%, a change within normal variation.

Raw presence declined 8.8 points from 35.4% to 26.6% across the series, while top-three rate fell 10.7 points and rank-one rate dropped 4.1 points. In September, the brand held 53 valid recommendations of 350 observations, with 6 rank-one placements. The August-to-September stability suggests the sharp July-to-August decline may have stabilized.

Core Peptides now holds second place, the highest position among the non-leading brands. Its September coverage level, while well below July, remained ahead of Biotech Peptides and AminoVault.

Highest-priority diagnostic: Which prompts previously returned Core Peptides as a top recommendation in July that no longer do, and whether the September stabilization is durable or a pause in a longer decline.

Biotech Peptides: Significant Decline with Partial Recovery

Biotech Peptides fell 9.2 points from 22.3% in July to 13.1% in September, a significant decline. The sharpest single-month move was a 10.6-point drop between July and August. Between August and September, the brand recovered 1.4 points to 13.1%, a change within normal variation.

Top-three rate fell 9.3 points from 16.4% to 7.1% across the series, and rank-one rate dropped 8.6 points from 10.6% to 2.0%, with just 7 rank-one placements in September. Net sentiment softened from 0.8 to 0.7. The brand's raw presence declined 5.0 points to 27.1%, a change within normal variation.

Biotech Peptides remains the second-most present brand in the category at 27.1%, but its recommendation conversion weakened measurably. The brand is visible but increasingly named without being recommended.

Highest-priority diagnostic: What attributes are associated with Biotech Peptides in its remaining positive recommendations, and which competitor captures the rank-one recommendation when Biotech Peptides is named but not chosen?

Blue Sky Peptide: Significant Rise from a Small Base

Blue Sky Peptide rose 5.0 points from 0.4% in July to 5.4% in September, a significant increase from a small base. The brand climbed 4.4 points between July and August, then added 0.6 points into September, a change within normal variation for the most recent month. The trend is upward across the full series.

Raw presence rose 6.0 points from 1.1% to 7.1%, with the brand present in 25 of 350 September observations. Valid recommendation count grew from 1 in July to 19 in September. However, top-three rate was 0.0% in September and rank-one placements were zero, meaning Blue Sky Peptide appeared in recommendations but never as a top-three or leading choice.

Blue Sky Peptide gained meaningful visibility and mid-tier recommendation placement across the three months, but it does not yet reach the top recommendation positions. The movement is from near-invisibility to a consistent presence in the broader recommendation set.

Highest-priority diagnostic: Which prompt themes introduced Blue Sky Peptide into AI answers, and what evidence sources are surfacing the brand at mid-ranking rather than top-three positions?

Buyer-Intent Interpretation

All 350 qualified September observations fell into the Brand Recommendation class. Both the Pricing & Value and Multi-Brand Comparison classes contained zero observations, meaning the public benchmark cannot yet answer commercial questions about price positioning, value perception, or head-to-head comparison dynamics.

The buyer-intent mix is therefore centered entirely on direct recommendation queries. This means the data speaks to which brands win when a buyer simply asks for a supplier recommendation, not to how brands fare when buyers weigh pricing options or compare suppliers side by side. Those questions would require additional research beyond the current benchmark scope.

Brand Opportunity Summary

The benchmark identifies where attention is warranted; a company-level analysis is needed to explain why.

Evidence Behind the Benchmark

The aggregate metrics are built from prompt-level observations covering the query, the AI surface, the recommendation outcome, rank, sentiment, and citations where exposed. Company-level analysis can go deeper into prompt, competitor, surface, and evidence patterns. Source presence is not automatically treated as proof of causation.

About This Benchmark

This report is part of the LLM Authority Index AI Market Discovery research program.

• AI Industry Market Discovery
• AI Industry Market Discovery Methodology
• AI Industry Market Discovery Metrics
• AI Industry Market Discovery Standards

Report-Specific Interpretation Notes

• Movement in this category is calculated against a qualified denominator that grew from 274 observations in July to 350 in September. Comparisons are made between the qualified sets, not the raw collections, and the denominator grew in each of the three measured months.
• Small counts warrant caution. Peptide Tech holds zero valid recommendations, Peptides Source holds 3, and Blue Sky Peptide holds 19, so percentage movements for these brands can appear large relative to a small base.
• Directional analysis identifies changes worth investigating; it does not by itself establish the cause of those changes. The three-month series shows broad category compression, but the drivers sit beneath the aggregate rates.

Next Step

The Public Benchmark Shows Where a Brand Is Winning or Losing. A Company-Level Audit Shows Why.

The aggregate percentages in this report raise questions that sit beneath the surface: which high-intent prompts are won, which competitor takes the recommendation when a brand loses, what attributes AI associates with each option, and which external sources shape those answers. For a category where no brand exceeded 18.6% coverage in September and three significant decliners compressed the field, the prompt-level detail matters as much as the headline rate.

A company-specific AI visibility audit maps those prompt, surface, competitor, ranking, sentiment, and evidence-source patterns into a prioritized visibility strategy. It moves from what changed to why it changed, and from category-wide movement to brand-specific diagnosis.

Request an AI visibility audit