Peptide comparisons, head to head

Each comparison puts two peptides that people weigh against each other in one table: what each was tested for, in how many people, its US and WADA status, and what is still unknown. Every row says whether it was tested in people, in animals or cells, or is a regulatory fact.

All comparisons

5 published. New ones are added as they are researched.

BPC-157 vs TB-500 BPC-157 vs TB-500: what each was tested for, and in whom For a tendon, the only head-to-head data is one 2026 study of 32 rats: TB-500 gave stronger repaired Achilles tendons than no treatment, BPC-157 also helped but not by a statistically clear margin, and giving both added nothing. In people, BPC-157 has six small reports, none of them a controlled injury trial, and TB-500 has never been tested on its own. For the gut, BPC-157 is the only one of the two with research, from rats and one colitis enema trial that did not clearly beat placebo. 21 sources, reviewed October 15, 2026
GHK-Cu vs AHK-Cu GHK-Cu vs AHK-Cu: what each copper peptide was tested for For hair, neither copper peptide has been tested on its own on a human scalp. AHK-Cu's case is one 2007 study in which human scalp follicles grew longer in a lab dish. The closest human hair data for GHK is a 45-patient placebo-controlled trial of GHK without copper, bound to 5-aminolevulinic acid, in which one of two strengths raised hair counts more than placebo. For skin and wounds, GHK-Cu has the only human trials of the two, and its two phase 3 wound trials did not beat placebo. 24 sources, reviewed October 16, 2026
Mazdutide vs Tirzepatide Mazdutide vs tirzepatide: what their trials found for weight loss In trials of Chinese adults with obesity or overweight, the two drugs beat placebo by similar margins: 15.15 percentage points for mazdutide's highest dose at 60 weeks (GLORY-2) and 15.1 for tirzepatide's highest dose at 52 weeks (SURMOUNT-CN). No trial has given both drugs. Tirzepatide has far more evidence behind it: worldwide phase 3 trials, a liver biopsy trial, a heart failure outcomes trial and FDA approval. Mazdutide is approved only in China, and a 2026 BMJ review rated its weight evidence low to very low certainty. 25 sources, reviewed October 18, 2026
Selank vs Semax Selank vs Semax: what each was tested for, and in whom If the question is anxiety, Selank is the one with patient data: two Russian studies of 62 and 70 people. If the question is the brain after a stroke, Semax is the one with patient data: Russian studies of 110 and 187 people. For focus or memory in a healthy person, neither has a trial, and Semax's own Russian label lists anxiety disorders as a reason not to use it. 19 sources, reviewed October 15, 2026
Survodutide vs Retatrutide Survodutide vs retatrutide: what their trials found for weight and liver fat Retatrutide lost more weight in its own trials: 25.0% at 80 weeks in its largest phase 3 trial against 13.0% at 76 weeks for survodutide, counting everyone randomized in both. The trials differed in length and placebo result, and no trial has given both drugs. Survodutide has more liver evidence: a biopsy trial in people with fatty liver inflammation and scarring, and FDA Breakthrough Therapy designation for that disease. Retatrutide's liver data so far are MRI scans of liver fat in 98 people. 22 sources, reviewed October 17, 2026

Build your own comparison

The comparison tool lines up any two or three peptides from the database: evidence grade, legal status, half-life and side effects.

Open the comparison tool Browse the peptide database How evidence is graded

Get each new comparison by email

The daily peptide brief: new trials, FDA actions and new pages, every source linked. Free.