# Thymalin

Russian thymus-extract bioregulator for immune 'renewal' in older people; thin evidence.

- Page: https://peprank.xyz/peptides/thymalin
- Category: Immune (Research peptide)
- Also known as: thymus polypeptide complex; Timalin
- Routes: Injection
- Safety tier: Strict: Caution · Balanced: Caution · Evidence only: Caution
- Risk axes (0 none to 3 severe): Seen harm 1, Mechanism 2, Data gap 1, Silent harm 1, Product 3
- Positive: 55% of 12 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #7 of 61 research peptides
- Graded reports: 12 (Glowing 2, Positive 5, Mixed 1, Nothing 2, Negative 1, Bad reaction 1)
- Evidence: Approved drug — approved in Russia; small, mostly unblinded human studies from one research group (Khavinson)
- Access: Grey market
- Onset: Nothing felt acutely; users judge it by fewer infections or changed immune labs over weeks to months
- Lasts: cumulative; one 10-20 day course is meant to last 6-12 months
- Cost per month: ≈ €13–54 (researchers' estimate)
- Updated: 2026-10-30

## What users report

Thin data: about a dozen first-hand reports, most of them on a multi-peptide stack. The positive half describe fewer colds or herpes outbreaks, gone allergies, better immune labs, or a cleared lingering infection. Two felt nothing. The negatives are a flu-like day on a 10 mg/day course, raised body temperature, and one user who blamed weeks of reflux and gastroparesis on a 4-day course. A long-time HSV user later grew wary of possible autoimmune or gut effects. Felt nothing: 2 of 13 reports (~15%); most users expect nothing acute, since a course is meant to show up as fewer infections over months.

**Effects:** fewer infections (anecdotal); improved lymphocyte markers (anecdotal); fewer herpes outbreaks (anecdotal)

**Downsides:** injection-site soreness; cost of repeated courses

**Risks:** Theoretical: immune stimulation in autoimmune disease (same logic as Ta1); Original drug is a calf-thymus extract; grey-market 'Thymalin' identity and purity are unverifiable

**Typical use:** 5-10 mg/day for 10 days, 1-2 courses per year.

**Getting it:** Russian-registered calf-thymus drug; outside Russia it is grey-market vials, often synthetic or mislabelled Thymogen/Thymulin

**Stacked with:** Epitalon (The classic Khavinson pairing, run as simultaneous 10-20 day courses once or twice a year; the 2003 mortality study combined them.); Thymosin alpha-1 (Run together or alternated by users chasing fewer infections, HSV control or autoimmune relief.); KLOW blend (Added alongside TA-1 by HSV and Hashimoto's users who credit the whole stack.)

## Risk profile

- **Seen harm 1/3:** The Russian label lists only possible allergic reactions and no study reports serious events, but there is no systematic safety reporting; one first-hand report describes a month of reflux and gastroparesis, confounded.
- **Mechanism 2/3:** A calf-thymus peptide extract given to stimulate immunity, so autoimmune or inflammatory flares are credible, as with thymosin alpha-1; chronic high doses caused thymic involution in animals.
- **Data gap 1/3:** Registered in Russia, but its own Belarus label says it was not studied in controlled trials; the human data are open studies from one group (266 elderly over 6-8 years, 80 COVID patients).
- **Silent harm 1/3:** Allergic, flu-like and immune effects would be noticed within days.
- **Product 3/3:** Outside Russia it is grey-market injectable vials, often synthetic or mislabelled thymulin; as an undefined extract its purity cannot even be specified.
- **Never if:** Active autoimmune disease or immunosuppression; Pregnancy or breastfeeding (label)

## Top reports

- Glowing, immune, 10 mg/day: “i was taking thymalin for immune modulation post covid and i saw it was used for antibiotic resistant clamydia. i was hopeful it might be useful for mycoplasma and it was. it cleared my infection.” — [r/MycoplasmaGenitalium](https://www.reddit.com/r/MycoplasmaGenitalium/comments/1rxq55s/thymalin_an_immune_modulating_peptide/)
- Glowing, immune: “KLOW, THYMOSIN ALPHA 1, and Thymalin has done wonders for my Hashimotos and Diverticulitis......game changer and life saver.” — [r/gravesdisease](https://www.reddit.com/r/gravesdisease/comments/1wujcin/anyone_tried_thymalin_or_thymosin_alpha_1_for/phthn5p/)
- Positive, immune: “For HSV2 I take 7 types of peptides: Ta1, KLOW blend (BPC-157, TB-500, GHK-CU and KPV), Thymalin, and LL-37. But I also take Lomatium twice a day which on its own reduces symptoms quite a bit, plus a number of supplements. My outbreaks and daily symptoms are much milder, but still present.” — [r/Holistichealing4HSV](https://www.reddit.com/r/Holistichealing4HSV/comments/1o1ad6u/anyone_tried_bpc157_motsc_for_chronic_fatigue_or/nifbv2w/)
- Positive, sleep: “It's not like it was while taking it but it sure is better than before starting it. Looking forward to another course and I think although the effects aren't as strong afterwards that it does make something of a lasting change.” — [r/Biohackers](https://www.reddit.com/r/Biohackers/comments/1h1yk8d/my_immune_system_results_using_thymalin/n2ml5l4/)
- Positive, immune: “-Thymalin - since I use it I don't have allergy and don't get sick as often as I used to.” — [r/Biohackers](https://www.reddit.com/r/Biohackers/comments/1dws8xr/best_peptides_for_autoimmune_vitiligo/lbz0ysd/)

## Cheapest in Europe

- [Europa-Peptide](https://europa-peptide.de/en/shop/thymalin-10mg/) (PL): Thymalin 10mg, €25, €2.49/mg
- [Particle Peptides](https://particlepeptides.com/en/buy-peptides/63-thymalin-20mg.html) (SK): Thymalin 20mg, €59, €2.93/mg
- [Baltic Peptides](https://balticpeptides.com/product/thymalin/) (LT): Thymalin 10mg, €40, €4.00/mg
- [CertaPeptides](https://certapeptides.com/shop/thymalin-10mg) (RO): Thymalin 10mg, €42, €4.20/mg

## Studies

- [Khavinson & Morozov, Peptides of pineal gland and thymus prolong human life (Neuro Endocrinol Lett 2003)](https://pubmed.ncbi.nlm.nih.gov/14523363/) (controlled, n=266, 2003): Over 6-8 years, elderly people given Thymalin courses had about half the respiratory infections and half the mortality of controls (single group, not blinded).
- [Kuznik et al., Peptide drug Thymalin regulates immune status in severe COVID-19 older patients (Adv Gerontol 2021)](https://pmc.ncbi.nlm.nih.gov/articles/PMC8654498/) (rct, n=80, 2021): Single-blind, placebo-controlled trial: 10 days of IM Thymalin on top of standard care gave faster lymphocyte and CRP recovery, and in-hospital mortality was halved.
- [Khavinson et al., Results and prospects of using activator of hematopoietic stem cell differentiation in complex therapy for patients with COVID-19 (Stem Cell Rev Rep 2021)](https://pmc.ncbi.nlm.nih.gov/articles/PMC7877506/) (controlled, n=92, 2021): Adding Thymalin to standard COVID-19 care sped the fall of IL-6, CRP and D-dimer and normalised T-cell counts faster than standard care alone.
- [Khavinson et al., The use of Thymalin for immunocorrection and molecular aspects of biological activity (2021)](https://pmc.ncbi.nlm.nih.gov/articles/PMC8365293/) (review, 2021): The originating group's review of 40 years of Russian clinical use in infections, immunodeficiency and ageing, almost none of it independently replicated.

## Sources

- [Khavinson & Morozov, Peptides of pineal gland and thymus prolong human life (Neuro Endocrinol Lett 2003)](https://pubmed.ncbi.nlm.nih.gov/14523363)