Scientific context only. Not medical advice, not a recommendation to use.
At a glance
Thymosin Beta-4 (Tβ4) is an endogenous 43-amino-acid peptide regarded as the principal intracellular actin-sequestering factor, involved in cell migration, neovascularisation and tissue regeneration. It has been studied in dry eye, corneal and wound healing, and cardiac repair (RegeneRx programmes, RGN-259). Thymosin Beta-4 is NOT an approved drug; robust human efficacy data are limited. The grey-market TB-500 is a synthetic fragment/analogue and is distinct from it.
Researched for
Dry eye diseaseCorneal and wound healingAngiogenesisCardiac repair (preclinical)
Official status
US: Unapproved
Not approved by the FDA as a medicinal product; under clinical development (including the ophthalmic RGN-259). Marketed in the grey market as a research substance.
Thymosin Beta-4 forms a 1:1 complex with monomeric (G-)actin and is regarded as the principal actin-sequestering factor in many cell types, thereby influencing cytoskeletal dynamics and directional cell migration. Preclinical models additionally describe effects on endothelial cell migration and neovascularisation, as well as activation of survival signalling pathways (including ILK/Akt). The mechanistic evidence derives predominantly from cell-culture and animal models.
02
Evidence at a glance
Reading note. The distribution shows on which evidence tier each observation sits. Strong colours mark stronger evidence — weaker tiers are deliberately visible, not hidden.
4 observations · 3 tiers
Human trial
1
Animal model
2
In vitro
1
03
What the studies show
Human trial
Mensch (Phase-2-RCT, ophthalmologische Lösung)
Sosne G et al. 2015
Improvement of signs and symptoms in severe dry eye disease
What does NOT follow: Small phase-2 trial (low participant number) using an ophthalmic formulation; results are not transferable to systemic use or other indications. Confirmation by larger trials is pending.
Animal model
Maus (db/db-diabetische und gealterte Tiere)
Philp D et al. 2003
Promotion of dermal wound healing
What does NOT follow: Animal-model finding — no confirming controlled human studies on dermal wound healing.
In vitro
Zellkultur (humane Endothelzellen, HUVEC)
Malinda KM et al. 1997
Stimulation of directional endothelial cell migration (angiogenesis-relevant)
What does NOT follow: In-vitro observation; says nothing about clinical efficacy in humans.
Animal model
Maus / Zellkultur
Bock-Marquette I et al. 2004
Promotion of cardiomyocyte survival and cardiac repair after infarction
What does NOT follow: Preclinical finding (animal model and cell culture); not transferable to humans without controlled human trials.
04
Where studies disagree
Open question
Do the preclinical regenerative effects of Thymosin Beta-4 translate into clinical benefit in humans?
POSITION A
Numerous animal and cell models show consistent effects on cell migration, angiogenesis and tissue regeneration; a small phase-2 dry-eye trial met significant endpoints.
POSITION B
Human evidence is limited to a few small studies (predominantly ophthalmic); controlled human trials for systemic indications such as cardiac repair are lacking. There is no medicinal-product authorisation.
CURRENT STATE · Well supported preclinically, but only sporadically and to a limited extent studied clinically. Broad clinical benefit in humans is not established.
05
Pharmacokinetics
No robust pharmacokinetic human data available. A model curve is not invented.
06d
Safer use & risks
Risk notes for harm reduction — descriptive, not a usage or dosing guide.
⚠ Important — please read
This platform does NOT provide usage or dosing instructions. The points below describe risks and are meant to help avoid harm — they do not replace medical advice. Anyone who uses a substance should discuss it with a doctor.
There is no approved human use for this substance. What circulates online about amounts and frequency is self-experimentation without a safety net.
Online numbers are not a benchmark
Amounts from TikTok, YouTube and forums are mostly imitation rather than data — and are often wrongly derived from animal studies (µg/kg). Not a reliable benchmark for humans.
Sterility & infection risk
Injection solutions prepared or stored non-sterile carry an infection and abscess risk. Contamination is common with grey-market product.
Unknown product quality
Research-/grey-market product is not quality-tested: identity, purity and actual content are often unknown, and counterfeits occur.
Mind interactions
Combinations with medications or pre-existing conditions can carry risks (see the Interactions section). Clarify with a doctor beforehand.
Warning signs — seek medical help
With persistent pain, redness/swelling at the injection site, fever, shortness of breath, racing heart, chest pain or allergic reactions, seek medical help immediately.
A doctor, not a forum
Concrete questions about use and amount belong in a conversation with a doctor — not in a comment thread.
07
Known adverse events from studies
Factual reporting of what studies observed. Not a safety statement for individual use.
Human trial
Well tolerated in phase 1 trials; no dose-limiting toxicity reported
Good acute tolerability does not replace long-term safety; grey-market TB-500 products are unverified in identity and purity.
Phase-1-Daten
07b
Interactions & combinations
Documented interactions and contraindications from studies, prescribing information and guidelines. Where no data exists, this is stated.
Reporting of risks, NOT a combination guide. The absence of an entry does not mean „safe to combine“ but „not sufficiently studied“.
No documented interactions recorded
We have not yet found robustly documented interactions for this peptide. This does NOT mean none exist — the data is limited.
10
Anecdotal observations
Weakest evidence tier — not supported by studies
Reading note. This section gathers popular claims from communities and forums. They are explicitly marked as weakest-tier evidence. Unblinded self-reports are particularly prone to placebo, recall and confirmation biases.
Why no amounts or protocols are listed here. We deliberately show only WHAT communities report — not in what amount or how it is used. Anecdotal "doses" or "biohacker protocols" are neither verified nor standardised nor safe; publishing them would be a usage guide, which we do not provide on principle. Specific amounts belong in a conversation with a doctor, not in a forum.
In sports and recovery communities, thymosin beta-4 — the body's own parent molecule of the grey-market fragment TB-500 — is discussed for tissue and wound healing as well as cardiac regeneration.
common, often equated with the fragment TB-500
Not supported by studies: Unlike the usual TB-500 fragment, recombinant/synthetic thymosin beta-4 has genuine phase 1 human safety data; robust human efficacy endpoints, however, remain limited.
11
Legal status by country
Country
Status
Note
Checked
United States
Unapproved
Not approved by the FDA as a medicinal product; under clinical development (including the ophthalmic RGN-259). Marketed in the grey market as a research substance.
2026-06-07
Germany
Unapproved
Not approved as a medicinal product; German drug (AMG) and advertising (HWG) law apply. No authorised medicinal product available.
2026-06-07
12
Reconstitution calculator
Pure mg/mL maths — works like a calculator. Not a usage recommendation.
Peptides ship as a dry powder. Once dissolved in a liquid (reconstitution), this calculator answers a single question: how much substance is in one millilitre of solution afterwards?
1Enter the vial's substance amount (printed on the label).
2Enter how much solvent you add.
3Result = concentration in mg per mL.
Printed on the label
/
Liquid you add
=
2.50
mg / mL
5 mg in 2 mL gives 2.50 mg/mL — each millilitre contains 2.50 mg of substance.