Thymosin beta-4
What it’s used for
Thymosin beta-4 (Tβ4) is a 43-amino-acid repair peptide involved in cell movement — the full-length molecule, not the shorter TB-500 fragment. People use it for wounds, surgery recovery and soft-tissue injuries, and as a topical for skin and wound healing. Human trials are small and formulation-specific, such as a 9-person dry-eye trial with eye drops; whether injections help recovery is unknown.
- Dry-eye relief Small human studies In a 9-person trial, 0.1% eye drops eased discomfort and corneal staining at day 56 versus drops without the peptide.
- Wound & injury repair Community reports Used for wounds, recovery after surgery and soft-tissue injuries.
- Topical skin healing Community reports Gels and creams are used for pressure and diabetic ulcers, burns, scars and hair-follicle research.
- Heart & nerve recovery Community reports Explored after heart attack and for vascular disease, stroke, and brain or spinal-cord injury.
What to expect
Injectable
- Weeks 1–12 Repair changes reported across this window; varies by condition
Topical
- Days 1–7 First response on the skin or wound
- Weeks 1–2 Visible change
- Weeks 2–8 Wound closure, depending on the condition
Side effects & safety
Side effects
No side effects documented yet.
Stop and get help if
- Signs of infection or drainage at the site
- A wound that gets worse
- Local reactions that don't go away
- Signs of an allergic reaction
- Heart or circulation symptoms
- Vision changes
Which symptoms mean call 911 or see a doctor
What regulators say
- There is no FDA-approved thymosin beta-4 product.
Why most peptides aren’t FDA-approved What’s really in “research use only” vials
Avoid or check first if
- Getting chemotherapy — a theoretical blood-vessel-growth concern
- Eye use with anything other than a sterile, eye-grade formulation
In sport
Banned at all times. Named in S2.3. It was at the center of the 2016 case in which 34 Essendon Australian football players were banned for two years.
Which peptides are banned in sport
How much people take
Injectable
Injectable
- Acute wound healing Daily · under the skin 1.6 mg
- Chronic tissue repair Twice weekly · under the skin 6 mg
- General regeneration Daily or every other day · under the skin 2–5 mg
- Research protocol As per study design · under the skin or IV (into a vein) 0.6–14 mg
- Cardiac protection Single dose · IV (into a vein), within 6 hours of a heart attack (MI) 42 mg IV · in a clinic
- Neurological recovery Three times over 72 hours · IV infusion 30 mg IV · in a clinic
Similar doses appear in 3 other sources
Topical
- Pressure ulcer healing Once daily · Direct Topical application to wound bed 1% gel
- Chronic wound care Twice daily · Applied to cleaned wound surface 0.5% cream
- Post-surgical care 2–3× daily · Applied to suture lines after closure 0.1–0.5% gel
- Burn treatment Every 8–12 hours · Applied to debrided burn areas 1% gel
- Anti-aging applications Once daily · Applied to face and neck areas 0.05% serum
In studies & labels
- Severe dry-eye symptoms Six times daily · Ophthalmic eye drops · 28 days, followed by 28 days observation Formulation-specific ocular study; no inference to injection. 0.1% RGN‑259 or vehicle
How to mix and store it
How many units do I draw?
Injectable
Open the full calculator
Injectable
How to mix 5 steps with bacteriostatic water · vial check
How to mix
- 1 Wipe both tops Wash your hands, then swab the rubber tops of the peptide vial and the water vial with alcohol. Let them dry.
- 2 Draw the water Use bacteriostatic (BAC) water — sterile water with a preservative, sold for mixing peptides . With a new sterile syringe, draw the amount you entered in the calculator. A 1 mL syringe filled twice is 2 mL.
- 3 Run it down the wall Push the needle into the peptide vial at an angle and let the liquid trickle down the glass, not onto the powder.
- 4 Swirl, don’t shake Gently swirl or roll the vial until the liquid is completely clear. Give it a few minutes if needed.
- 5 Label the vial Write the date and what you mixed (for example 5 mg + 2 mL) on the vial.
This is general practice. If your product came with its own diluent or instructions, follow those. Not sure what to buy? See the supplies checklist .
Is my vial OK?
Good signs
- Clear, colorless solution
Don’t use if
- Cloudy or discolored solution
- Crystallization after mixing
Injecting under the skin Where, rotating sites, which syringe
- Where: belly (at least 2 in / 5 cm from the navel), front of the thigh, or back of the upper arm.
- Rotate sites each time and skip bruised, scarred or sore skin.
- Syringe: most people use a U-100 insulin syringe with a short, thin needle (29–31 gauge, 8 mm or shorter).
- How: wipe with alcohol and let it dry, pinch the skin, go in at 45–90°, push slowly. Use each syringe once.
General practice for under-the-skin injections, not specific to Thymosin beta-4.
The full guide: how to inject safely
Storage
Fridge · 14 days Reported shelf life, not lab-tested. Mixed vial at 2–8°C (35.6–46.4°F) for up to 14 days; dry powder at room temperature
Topical
How to mix 5 steps with sterile water
How to mix
- 1 Wipe both tops Wash your hands, then swab the rubber tops of the peptide vial and the water vial with alcohol. Let them dry.
- 2 Draw the water Use sterile water . With a new sterile syringe, draw the amount your product calls for. A 1 mL syringe filled twice is 2 mL.
- 3 Run it down the wall Push the needle into the peptide vial at an angle and let the liquid trickle down the glass, not onto the powder.
- 4 Swirl, don’t shake Gently swirl or roll the vial until the liquid is completely clear. Give it a few minutes if needed.
- 5 Label the vial Write the date and what you mixed (for example 5 mg + 2 mL) on the vial.
This is general practice. If your product came with its own diluent or instructions, follow those. Not sure what to buy? See the supplies checklist .
Storage
Fridge · away from light Prepared gels or creams at 2–8°C (35.6–46.4°F); single-use containers preferred; no set shelf life
Combining it with others
AI assessment Based on how each compound works, not on studies of the combination. How we assess
Don’t combine 4
- Wolverine Stack Contains TB-500, a piece of thymosin beta-4, so you’d be doubling it.
- GLOW Contains TB-500, a piece of thymosin beta-4, so you’d be doubling it.
- KLOW Contains TB-500, a piece of thymosin beta-4, so you’d be doubling it.
- TB-500 TB-500 is a piece of thymosin beta-4, so taking both doubles the same thing.
Can be combined 8
ARA 290 BPC-157 Cartalax Thymosin alpha-1 LL-37 GHK-Cu KPV AHK-Cu
What the research says
Few human studies
- Human data is small: a 9-person dry-eye trial using eye drops, plus phase I safety studies of specific formulations.
- Nine trial participants are too few to reveal uncommon side effects.
- A small phase I study of NL005 found no dose-limiting toxicities or serious adverse events, but NL005 is a 44-residue investigational form.
- Whether injected Tβ4 helps tendon, muscle or ligament recovery is unknown, as is long-term safety.
- Taking it with other recovery peptides hasn't been studied for safety or benefit.
- Research powder is sold as a lab reagent, without clinical sterility or approval, and may not match clinical material.
- People often treat TB-500 and Tβ4 as the same thing, which muddles dose and outcome reports; fragment results don't transfer.
What studies found
- Severe dry eye: a small positive trial Nine participants received 0.1% RGN-259 or vehicle. At day 56, the treated group had lower discomfort and corneal staining. The small sample and eye-specific formulation limit generalization.
- Human testing is formulation-specific A randomized phase I study investigated recombinant human thymosin beta-4 in healthy Chinese volunteers. Safety and pharmacokinetic testing is not evidence of injury-healing efficacy.
A half-life hasn’t been verified for this compound.
What it’s made of
- Length
- 43 amino acids
- Molecular weight
- 4,963.4 Da
- Formula
- C 212 H 350 N 56 O 78 S
Sequence 43 · N → C
- S
- D
- K
- P
- D
- M
- A
- E
- I
- E
- K
- F
- D
- K
- S
- K
- L
- K
- K
- T
- E
- T
- Q
- E
- K
- N
- P
- L
- P
- S
- K
- E
- T
- I
- E
- Q
- E
- K
- Q
- A
- G
- E
- S
N-terminal acetylation.
Native-length N-acetylated sequence. NL005 in the cited phase I study is a 44-residue recombinant product; TB‑500 fragment is seven residues.
Sources
Sources 33
How this page was made
How it may work: Actin regulation influences cell migration, inflammatory signaling and angiogenesis.
Other names: Tβ4 · TB4 · TB-4 · Timbetasin · RGN-259 · Full-length thymosin beta 4
Preparation in studies: Clinical eye drops and laboratory powder have different preparation requirements.
Reference “proven” and “safe together” claims exceed evidence; fragment findings are not interchangeable.
Research last checked: Oct 12, 2026 (a targeted search, not a full review).
Community doses, how long people take it, timing and storage are compiled with AI from public peptide guides, clinics and forums, cross-checked against other sources where we could, and rewritten in plain language. “Combining it with others” is an AI assessment of how the compounds work. Study notes are written from each paper’s abstract where one exists. How we source
Original source guide