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Peptide Evidence Registry

Comparison Centre

Two compounds, the same questions, no cherry-picking

Marketing compares compounds on whichever measure flatters them. This compares them on the same fields every time — including the awkward ones like how much human safety data exists. Every score here rates the evidence, not the compound: a higher number means stronger or more mature research, not that something is safer or works better.

Sharing keeps the two compounds you picked.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

Thymosin alpha-1

A thymic immune peptide approved in dozens of countries for specific indications, but never approved in the US — and marketed far beyond any approval.

L3Early human studiesApproved in some countries only · See jurisdiction details
Full profile

KPV

A three-amino-acid fragment of alpha-MSH marketed for gut healing and inflammation, with no human clinical studies identified by the FDA.

L1Theory onlyResearch / unapproved supply
Full profile

How far human research has progressed

Thymosin alpha-1

Approved in multiple non-US regions for specific indications; studied in oncology and infectious disease settings

KPV

Preclinical only; no human studies identified

Claim-specific benefit evidence

A human exposure study or trial registration does not establish that the claimed benefit occurs.

Thymosin alpha-1

Not separately assessed; see the full profile.

KPV

Not separately assessed; see the full profile.

Human research context

Thymosin alpha-1

Approved in multiple non-US regions for specific indications; studied in oncology and infectious disease settings

KPV

Preclinical only; no human studies identified

Human efficacy evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Thymosin alpha-1

Strength of the human efficacy evidence45 of 100 evidence strength

KPV

Strength of the human efficacy evidence5 of 100 evidence strength

Preclinical (animal / lab) evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Thymosin alpha-1

Strength of the animal and lab evidence55 of 100 evidence strength

KPV

Strength of the animal and lab evidence35 of 100 evidence strength

Human safety evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

Thymosin alpha-1

Strength of the human safety evidence45 of 100 evidence strength

KPV

Strength of the human safety evidence5 of 100 evidence strength

Regulatory status (legal position, not proof it works)

Thymosin alpha-1

Check jurisdiction-specific details in the profile.

Not FDA-approved. The FDA's 2024 advisory review notes approvals in parts of Asia-Pacific, Latin America, Eastern Europe and the Middle East for various indications. Those approvals are region- and indication-specific; they do not generalise to 'immune boosting' in healthy people or to US availability.

KPV

Check jurisdiction-specific details in the profile.

No FDA-approved product exists. FDA's Pharmacy Compounding Advisory Committee considered KPV in July 2026 for possible inclusion on the 503A Bulks List. Its recommendations are non-binding: this compounding-policy process is not FDA drug approval or validation of efficacy claims. FDA briefing material states that no clinical studies or human exposure data for KPV via any route were identified and that human safety risks are unknown.

Common claims

Thymosin alpha-1

  • · Boosts immune function
  • · Adjunct benefit in hepatitis and some cancers
  • · General immune 'optimisation' in healthy people

KPV

  • · Heals the gut lining in IBD and leaky gut
  • · Reduces systemic inflammation

How settled our evidence rating is

Thymosin alpha-1

Moderate confidence in ratingL3Early human studies

KPV

Very low confidence in ratingL1Theory only

Cancer-related questions raised by the biology

These are theoretical or monitored questions raised by how a compound works. They are not evidence that it causes cancer.

Thymosin alpha-1

Studied as an immune adjunct in oncology settings — a therapeutic research context, not evidence it prevents or treats cancer as marketed online.

KPV

No data in humans either way; unstudied.

What this adds up to, in plain English

Thymosin alpha-1

Preliminary human observations exist, but they may not establish a treatment-attributable benefit.

KPV

This sits in theory and anecdote. Popular claims about it should be treated with very low confidence.

A comparison is not a recommendation

Neither column here is an endorsement, and the compound with the higher numbers is not the “better” or “safer” one — it is simply the one with more or better-quality research behind it. Two compounds can both be poorly evidenced, and better-evidenced says nothing about whether either is a sensible idea for a specific person. That is a conversation for a qualified clinician.