These 4 work in 3 different ways, so they are not straight substitutes for each other.
| Comparison | BPC-157 Body Protection Compound 157 · Pentadecapeptide BPC 157 | TB-500 / Thymosin Beta-4 TB4 · thymosin beta 4 | Cartalax AED · Ala-Glu-Asp | PDA (Pentadeca Arginate) pentadeca arginate · BPC-157 arginate |
|---|---|---|---|---|
| How it works | How it works BPC-157 is a 15-amino-acid chain based on a protective protein found in stomach acid. It is one of the most widely used peptides here and one of the least studied in humans. | How it works TB-500 is a fragment of thymosin beta-4, a protein your body already uses when tissue needs repairing. Its main job is helping cells move. | How it works Cartalax is three amino acids, marketed for cartilage and joint tissue. | How it works PDA is BPC-157 as an arginate salt rather than an acetate salt. The peptide chain is the same; the counter-ion is different. |
| What it is | A popular healing peptide for injuries, gut, and joint or tendon pain. | A recovery peptide for healing muscle and tendon, often paired with BPC-157. | A bioregulator for cartilage and joint health, with thin evidence. | A newer, more stable cousin of BPC-157 for faster healing. |
| Status | Research only | Research only | Research only | Research only |
| Typical dose | 0.25–0.5 mg per dose | 2–2.5 mg per dose | 2–5 mg per day | 0.25–0.5 mg per day |
| How often | 1-2x daily | Twice a week | Courses | 1-2x daily |
| Stays active | About 8 to 30 minutes in rats | Not established | Nothing published | Nothing published |
| Dose comes from | Community practice | Community practice | Community practice | Community practice |
| Cycled? | Commonly run in 4 to 8 week blocks around an injury, then stopped Community practice | Commonly a loading period of 4 to 6 weeks, then less often, then stopped Community practice | Courses of 10 to 20 days, repeated two or three times a year Community practice | Commonly run in 4 to 8 week blocks, like BPC-157 Community practice |
| What it does | ||||
| Drug class | Repair peptide | Repair peptide | Bioregulator peptide | BPC-157 relative |
| Used for | A popular healing peptide people use to bounce back faster from injuries, gut problems, and joint or tendon pain. It is a favorite for recovery. | A recovery peptide used to heal muscles, tendons, and other injuries faster and move more freely. It is often paired with BPC-157. | A bioregulator aimed at cartilage and joint health, taken in short courses. | A newer, more stable cousin of BPC-157, used for the same thing: faster healing of gut, tendons, muscle, and inflammation. It is marketed as longer-lasting. |
| Receptors hit | — | — | — | — |
| Numbers | ||||
| Full dose line | 0.25 up to 0.5 mg per dose (start low, increase slowly) | 2 up to 2.5 mg per injection (start low, increase slowly) | Varies (course-based) | 0.25 up to 0.5 mg per day (start low, increase slowly) |
| Why that cycle | The block length is a community convention tied to how long a soft-tissue injury takes to settle. No human study has tested a duration, and none has looked at what long-term use does, so there is no evidence either that a break is needed or that it is safe to skip one. | The loading-then-maintenance shape comes from community practice. No human study has tested a duration or a break. | The course structure is how the Khavinson protocols specify these and how they are sold. No trial has compared course dosing against continuous use, or established how long the gap between courses should be. | Same convention as BPC-157, which it is a salt form of. No human study has tested a duration. |
| Weight / effect | Not measured in a trial | Not measured in a trial | Not measured in a trial | Not measured in a trial |
| Chain length | 15 residues | 43 residues | 3 residues | 15 residues |
| Common vial | 5 mg | 10 mg | 10 mg | 10 mg |
| Before you start | ||||
| Route | Under the skin, into muscle, or by mouth | Under the skin or into muscle | Under the skin (subcutaneous) | Under the skin (subcutaneous) |
| Do not use if | Active cancer, as a precaution given that it promotes new blood-vessel growth Pregnancy Banned in drug-tested sport | Active cancer, as a precaution given the tissue-growth mechanism Pregnancy Banned in drug-tested sport | Pregnancy or breastfeeding Any prescription medicine you take regularly, without checking for interactions first Anyone who wants established safety data, because none exists for this compound in humans | No published human trials exist, so no contraindications are established Pregnancy Active cancer, as a precaution given the healing mechanism |
What separates them
Proof behind the dose. Every dose here comes from community practice. Not one is backed by a published human study, which is worth knowing before you read the numbers as if they were equivalent.
How you take it. BPC-157 is sold by mouth and injected. TB-500, Cartalax and PDA are injected.
What doesn't differ: None of them has a measured effect size from a published trial, so there is no number to rank them on.
What people actually report
BPC-157
- Almost all the evidence so far is from animal studies, not people.
- There is a theoretical cancer concern because it promotes new blood-vessel growth.
- Banned in drug-tested sport.
- Signs of an allergic reaction
- New lumps or masses
TB-500 / Thymosin Beta-4
- It is mostly tested in animals, with limited human data.
- Most products sold are a fragment rather than the full protein.
- Banned in drug-tested sport.
- Signs of an allergic reaction
- New lumps or masses
Cartalax
- Little human evidence.
- Spreading hives, swelling of the face or throat, or trouble breathing, which can happen with any injection and is a medical emergency
- Redness, heat, or pus at the injection site, which can signal infection
PDA (Pentadeca Arginate)
- It is very new, with little formal data, and carries the same blood-vessel-growth cancer caution as BPC-157.
- Signs of an allergic reaction
- Anything unusual, given the absence of human data
Side effects are what users and trials report most often, not a complete list. Anything sudden, spreading, or breathing-related is an emergency regardless of which compound caused it.
People also compare
This comparison does not cover cost, long-term safety, or how you personally will respond. Effect figures come from separate trials in different populations and are not always directly comparable to each other. Nothing here is medical advice or a recommendation to use any of these. Talk to a clinician about your own situation.