Since using thymic/immune peptides (from a reputable supplier) - specifically Thymalin, Thymulin, and TA-1 -- I have absolutely nothing, not even the tiniest symptom, for more than a year.
Positiveabout a year of experimenting with thymic peptides
HSV-2; stacked with Thymalin and TA-1; says her vial labelled 'Thymalin' was actually the thymulin nonapeptide
Anecdotally they have had long lasting benefits as I did a course 1 year ago and I’ve had less brain fog since, but I don’t know how much of it is placebo or in general and increase in my health as a whole because there are so many other factors.
PositiveInjection · one course a year earlier
CIRS; thymulin and Vilon as one course inside an eight-peptide stack (VIP, TA-1, KPV, LL-37, BPC-157)
Was super expensive and I dont remember if they worked or not. Cost me about 1K per month. Topical Dutasteride worked for sure but unsure about the rest
NothingSkin & hair · Topical · about a year (2019)
Androgenetic alopecia; GHK-Cu with Zn-thymulin topical alongside topical dutasteride/latanoprost, TB-4 injections and PTD-DBM/valproic acid; credits only the dutasteride
Users report
Too few reports to judge: four first-hand accounts, three of them on multi-peptide or multi-drug stacks. Two injectors credit it. One HSV-2 user had no symptoms for over a year on a Thymalin, thymulin and TA-1 course, though a prodrome came back months later. One CIRS user had less brain fog for a year after a thymulin and Vilon course and wonders if it was placebo. A second CIRS patient two weeks into prescribed injections could not tell whether anything had changed. A hair-loss user who ran a GHK-Cu/zinc-thymulin topical for a year among several treatments cannot say it did anything. Users also mix it up with Thymalin: one HSV user's vial labelled 'Thymalin' turned out to be thymulin. Felt nothing: 2 of 4 reports; too few reports to judge.
Best effects
Fewer infections or herpes outbreaks (anecdotal, stacked) · less brain fog in CIRS (anecdotal, stacked) · new vellus and intermediate scalp hairs (one small open-label topical series)
Downsides
Daily injections in the only controlled trials (1-10 mg/day subq) · cost of compounded scalp foams and serums · no felt effect to confirm it is working
Watch
Theoretical: an immunomodulator in people with autoimmune disease or lymphoid cancer (one Reddit user with CLL was about to inject it); the 1980s rheumatoid-arthritis trials saw no flares, but the data are thin · Grey-market vials are mostly the zinc-free nonapeptide, which is inactive unless zinc binds it, and identity, sterility and endotoxin are unverified · Name confusion with Thymalin (Russian calf-thymus extract) means people may not get the molecule they think they bought
Evidence
Small human studies — Two small double-blind rheumatoid-arthritis trials and immunodeficiency case reports from the Bach/Dardenne group in the 1980s, plus one uncontrolled 18-person topical hair series (2017); nothing modern, no approval anywhere
Caveat
Almost everything known about thymulin as a drug comes from one Paris group in the 1980s; the topical hair claim rests on a single uncontrolled series and organ-culture work. The molecule needs zinc bound to be active, and most research vials are sold zinc-free, so what people inject may do nothing. Thymuskin's Reddit reports (some regrowth, some shedding and red scalp) are about a thymus-extract product and are not counted here.
Typical use
No established dose. The rheumatoid-arthritis trials used 1-10 mg/day subq (5 mg best), daily for two weeks and then three times a week; grey-market courses are improvised. Topical: daily scalp spray or foam.
Getting it
Not approved anywhere. Sold as 10 mg research vials (often the zinc-free peptide), occasionally prescribed by functional-medicine clinics, and compounded as GHK-Cu/zinc-thymulin scalp foams and serums. Thymuskin is a different product: a thymus-peptide hair line, not pure thymulin.
Stacked with
Thymalin and thymosin alpha-1: Run together as 'thymic peptides' by HSV and CIRS users, which makes thymulin's own effect impossible to separate. · Vilon, VIP, KPV: Part of CIRS protocols, with thymulin and Vilon as the short 'immune gene regulator' course. · GHK-Cu (topical): The usual commercial scalp pairing, sometimes with PTD-DBM, alongside or instead of minoxidil.
Since using thymic/immune peptides (from a reputable supplier) - specifically Thymalin, Thymulin, and TA-1 -- I have absolutely nothing, not even the tiniest symptom, for more than a year.
Positiveabout a year of experimenting with thymic peptides
HSV-2; stacked with Thymalin and TA-1; says her vial labelled 'Thymalin' was actually the thymulin nonapeptide
Anecdotally they have had long lasting benefits as I did a course 1 year ago and I’ve had less brain fog since, but I don’t know how much of it is placebo or in general and increase in my health as a whole because there are so many other factors.
PositiveInjection · one course a year earlier
CIRS; thymulin and Vilon as one course inside an eight-peptide stack (VIP, TA-1, KPV, LL-37, BPC-157)
Was super expensive and I dont remember if they worked or not. Cost me about 1K per month. Topical Dutasteride worked for sure but unsure about the rest
NothingSkin & hair · Topical · about a year (2019)
Androgenetic alopecia; GHK-Cu with Zn-thymulin topical alongside topical dutasteride/latanoprost, TB-4 injections and PTD-DBM/valproic acid; credits only the dutasteride
Its difficult because I'm so brain foggy but I guess i misunderstood thymulin is meant more to stop infections and support the immune system not nessecary be a key in switching off inflammation
NothingInjection · about 2-4 weeks
CIRS; injections prescribed by a functional-medicine doctor
Safety
Tier by safety barStrict CautionBalanced CleanEvidence only Clean
Small human studies only: two 1980s rheumatoid-arthritis RCTs and case reports from one Paris group, and one uncontrolled 18-person topical series. No approval anywhere and nothing modern. The trials used synthetic zinc-thymulin, the same molecule sold today, though most vials are sold zinc-free. Amor et al. 1987 (PubMed) ↗Superpower peptide guide: thymulin (no modern interventional trials) ↗
Silent harm 1/3
The harms most plausible for what people actually inject are injection-site and contamination reactions and a flu-like flare, all noticed within days. A slower immune effect, such as an autoimmune flare, would mostly show as symptoms but could take weeks to appear. Mendias & Awan 2026 preprint: grey-market peptide quality failures and endotoxin ↗
Pregnancy or breastfeeding (no human reproductive data) · Organ transplant or other immunosuppressive therapy · Lymphoid cancers such as CLL or lymphoma, where T-cell stimulation is untested
Prasad et al., Serum thymulin in human zinc deficiency (J Clin Invest 1988)observational · n=14 · 1988 Thymulin activity in blood depends on zinc: it fell in mildly zinc-deficient adults (two induced by diet, twelve with existing deficiency) and recovered with zinc repletion, along with their T-cell subsets and IL-2.
Each bead is one amino acid in the peptide's chain, coloured by its side chain: grey for non-polar, cyan for polar, blue for positively charged and fuchsia for negatively charged. Length and mix tell related peptides apart at a glance, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4. The colours describe chemistry only and predict neither effect nor safety.
non-polarpolarpositivenegative
Report grades
Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.
GlowingPositiveMixedNothingNegativeBad reaction
% positive
The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Kept peptides rank by the same reports' mean grade, shrunk the same way, and excluded ones follow in that order.
Researcher estimate
No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks alongside the computed scores until reports arrive.
Safety tier
Each peptide is tiered clean, caution or excluded from its five risk axes under the chosen safety bar. An excluded peptide has a plausible route to serious harm, so it stays listed with the reason but ranks behind every other entry, however good its reviews.
Safety bar
The safety bar sets how much risk it takes to exclude a peptide. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.
Seen harm
Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.
Mechanism
A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.
Data gap
How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.
Silent harm
Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.
Product
The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin.
Evidence
The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.
Access
How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.
Price per month
Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. Prices are in euros at ECB rates of 2026-10-29, before shipping; the shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.
Dose users report
The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.
Testing
Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.
Added peptide
Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.