Ranked by Finnrick trust score, purity testing, and price.
Polaris Peptides is our #1 pick for Thymulin, with a Finnrick trust score of 7.3/10. Across 4 tracked vendors, prices range from $39.99 to $185.00, verified by Peptide Compare on 23 Sep 2026. Prices are scraped from vendor sites; trust scores come from Finnrick blind tests.
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| Rank | Vendor | Trust score | Per mg |
|---|---|---|---|
| #1 | Polaris Peptides | 7.3/10 | $1.85 |
| #2 | Simple Peptide | 7.0/10 | $4.20 |
| #3 | AMC Essentials | untested | $4.00 |
| #4 | Southern Aminos | untested | $9.38 |
Our composite score weighs Finnrick blind-testing trust scores (62%), price competitiveness (25%), and stock availability (13%). Vendors without Finnrick data are sorted by price below scored vendors. We never accept payment for rankings. Learn more.