# Ac-SDKP — dosage, half-life & reference guide | PepVault

Source: https://pepvault.app/peptides/tb-500-fragment

Last updated: 2026-10-09

[Library](https://pepvault.app/peptides) [Healing & recovery](https://pepvault.app/peptides#healing) reviewed October 2026

# Ac-SDKP Dosage, half-life & reference guide

Also known as TB-500 Fragment · TB-4 Frag · Goralatide · Thymosin Beta-4 (1-4)

The first four amino acids of thymosin beta-4, sold as a 'TB-500 fragment' though it isn't part of TB-500. In rodent studies it calms inflammation and scarring in the heart, kidneys and lungs and helps new blood vessels form; no study has looked at tendons or ligaments.

- **Studied range:** 250–750 mcg
- **How often:** EOD
- **Half-life:** ~4.5 min
- **Evidence:** Emerging
- **Route:** SubQ injection

Studied in research — not a recommendation.

[Ac-SDKP dose guide](https://pepvault.app/lab/dosage/tb-500-fragment)

## How it works.

Isolated N-terminal tetrapeptide of Thymosin Beta-4, residues 1–4; TB-500 itself is residues 17–23, so this isn't part of TB-500. In rodent and cell studies it is anti-inflammatory and anti-fibrotic in heart, kidney and lung models and promotes angiogenesis and cell migration. It is cleared by ACE within minutes, and ACE inhibitors raise its blood levels about fourfold.

**Commonly reported:** Community data are sparse, and users who report on it describe it much like TB-500, a gradual easing of soft-tissue aches.

### Half-life & active level

The half-life of Ac-SDKP is ~4.5 min (measured in healthy volunteers after IV; cleared by ACE, and a SubQ dose peaks in about 15 minutes).

Here's how a typical Ac-SDKP schedule plays out over 48 hours (one-compartment estimate).

An estimate from the half-life above, not a measurement. See your own curve build live in [the half-life calculator](https://pepvault.app/tools/peptide-half-life-calculator).

## Where Ac-SDKP works.

- ### Heart & blood vessels

  **In animals.** In rodent studies it calms inflammation and scarring in the heart, kidneys and lungs and helps new blood vessels form.
- ### Joints & tendons

  **Reported by users.** Users who report on it describe it much like TB-500, a gradual easing of soft-tissue aches.

An area lights for what a peptide is used for and what people report, with the evidence beside it. It isn’t a promise that it works there.

## Mixing and a typical run.

Example numbers

### Reconstitution example

Reconstitute a 5 mg vial of Ac-SDKP with 2 mL of bacteriostatic water and a 500 mcg dose is 20 units on a U-100 syringe, about 10 doses per vial.

- **Vial:** 5 mg
- **Water:** 2 mL
- **Amount:** 500 mcg

Draw to **20 units**

0.3 mL insulin syringe · 30 units

[Mix it in the Reconstitution Lab](https://pepvault.app/lab) [Open the calculator](https://pepvault.app/tools/reconstitution-calculator)

### Run notes

- **Cycle:** 6-8 week cycles typical. Preferred over full TB-500 by some for targeted tendon/ligament work. Community practice — opinions vary. Not a clinical recommendation.
- **Timing:** SubQ near area of injury or rotate standard sites. Timing flexible.
- **Route:** SubQ injection
- **Stacks:** BPC-157, TB-500, GHK-Cu

## Safety.

### Common side effects

- Injection site reaction
- Fatigue
- Headache

## Goes with.

- [BPC-157](https://pepvault.app/peptides/bpc-157)
- [TB-500](https://pepvault.app/peptides/tb-500)
- [GHK-Cu](https://pepvault.app/peptides/ghk-cu)

## Questions people ask.

### What is Ac-SDKP?

The first four amino acids of thymosin beta-4, sold as a 'TB-500 fragment' though it isn't part of TB-500. In rodent studies it calms inflammation and scarring in the heart, kidneys and lungs and helps new blood vessels form; no study has looked at tendons or ligaments.

### How is Ac-SDKP dosed in research?

The research range for Ac-SDKP is 250–750 mcg, EOD or twice weekly. Studied in research — not a recommendation.

### How long does Ac-SDKP last?

The half-life of Ac-SDKP is ~4.5 min (measured in healthy volunteers after IV; cleared by ACE, and a SubQ dose peaks in about 15 minutes).

### What do people report on Ac-SDKP?

Commonly reported on Ac-SDKP: community data are sparse, and users who report on it describe it much like TB-500, a gradual easing of soft-tissue aches.

### Is Ac-SDKP safe?

The research basis for Ac-SDKP is emerging: primarily preclinical / limited human data. Common side effects in the library: injection site reaction, fatigue and headache.

### What does Ac-SDKP stack with?

Common stacks for Ac-SDKP: BPC-157, TB-500 and GHK-Cu.

## Research.

The literature

### Search the latest research

[PubMed](https://pubmed.ncbi.nlm.nih.gov/?term=Ac-SDKP) [Google Scholar](https://scholar.google.com/scholar?q=Ac-SDKP)

## Reference.

- **Cadence:** EOD EOD or twice weekly.
- **Half-life:** ~4.5 min ~4.5 min (measured in healthy volunteers after IV; cleared by ACE, and a SubQ dose peaks in about 15 minutes)
- **Research basis:** Emerging Primarily preclinical / limited human data

## More healing & recovery peptides

- [KPV 100–300 mcg](https://pepvault.app/peptides/kpv)
- [AOD-9604 250–300 mcg](https://pepvault.app/peptides/aod-9604)
- [Thymosin Alpha-1 1–1.6 mg](https://pepvault.app/peptides/thymosin-alpha-1)
- [Thymosin Beta-4 2–2.5 mg](https://pepvault.app/peptides/thymosin-beta-4)
- [LL-37 100–300 mcg](https://pepvault.app/peptides/ll-37)
- [Larazotide 0.5–1 mg](https://pepvault.app/peptides/larazotide)

## Free tools

- [Ac-SDKP dose guide](https://pepvault.app/lab/dosage/tb-500-fragment)
- [Reconstitution Lab (3D)](https://pepvault.app/lab)
- [Injection guide (3D)](https://pepvault.app/lab/injection)
- [Peptide Sky (3D)](https://pepvault.app/lab/sky)
- [Peptide tier list](https://pepvault.app/lab/tiers)
- [Reconstitution calculator](https://pepvault.app/tools/reconstitution-calculator)
- [Half-life & active level](https://pepvault.app/tools/peptide-half-life-calculator)

PepVault for iPhone

## Track Ac-SDKP in PepVault

Log every dose, keep your vial and the doses left in it and watch its estimated active level. 7 days free on the yearly plan for new subscribers.

[Download on the App Store](https://apps.apple.com/app/apple-store/id6779318649?pt=129020030&ct=peptides-cta&mt=8)

[Open the calculator](https://pepvault.app/tools/reconstitution-calculator) [How the vial count works](https://pepvault.app/peptide-vial-tracker-app) [Explore the live demo](https://pepvault.app/login)

Reviewed October 2026 [How we check the library](https://pepvault.app/about#library)

PepVault is a research and tracking resource, not medical advice. Ranges are what studies used, never a dose for you. Brand names are trademarks of their owners; PepVault is independent of them.

PepVault is a private research and tracking tool, not medical advice. The information here is reference material from published literature and community use — always verify it and discuss any protocol with a qualified clinician before changing it.

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