B7-33 (B7-33 (Relaxin Peptide Analog))
A single-chain peptide analog of the hormone relaxin, researched for its anti-fibrotic and cardiovascular/organ-protective effects. Biohackers track it for potential anti-fibrosis and tissue-remodeling benefits; it remains preclinical.
How it works
Selectively activates the relaxin receptor RXFP1 pathway, biasing signaling toward anti-fibrotic effects. It reduces collagen deposition and promotes healthy tissue remodeling in heart, lung, and kidney models without some downsides of full-length relaxin.
Key facts
- Molecular weight: ~3.3 kDa
- Half-life: Short (peptide)
- Bioavailability: Injection (research)
- Storage: Lyophilized: -20°C. Reconstituted: 2-8°C.
Dosing overview
- Typical dose: Not established for humans
- Frequency: Research only
- Duration: Research only
- Route: Injection (research)
Protocol notes
- No validated human dosing exists; all use is experimental and unapproved.
- Animal studies used weight-based injectable dosing for anti-fibrotic effects.
- Included for educational completeness.
Reported benefits
- Anti-fibrotic effects (preclinical)
- Cardiac and organ protection (research)
- Healthy tissue remodeling
- Relaxin-pathway (RXFP1) biased signaling
Possible side effects
- Unknown human safety
- No approved human use
- Unproven efficacy in humans
Research
- B7-33 reduces fibrosis (2016): The relaxin analog B7-33 reduced fibrosis in heart, lung, and kidney models via biased RXFP1 signaling.
Community reviews of B7-33
- quiet_gains rated it 5/5 - Noticed clear benefits within weeks: Added B7-33 to my protocol about 3 months ago and it has earned its place. The benefits became noticeable around week 2-3 and have been consistent since. What I appreciate about this compound is the predictability. It does what the research suggests it should do, at roughly the timeline you would expect. No surprises, no dramatic swings, just steady improvement. No notable side effects to report at my dose. Sourcing is always the challenge with research compounds, insist on third-party testing. Storage and reconstitution per standard protocols. Plan to continue.
- titration_tara rated it 5/5 - Worth adding to the protocol: B7-33 has been a worthwhile addition. I am data-driven and tracked relevant markers before, during, and after. The improvement is measurable and correlates with the intervention timeline. What sets this apart from some compounds I have tried is the consistency. Benefits did not fluctuate wildly or disappear. They built up and maintained. That gives me confidence in the mechanism. Tolerance has been excellent. Nothing in my bloodwork or subjective experience raised any flags. This is the kind of compound that does its job quietly without causing problems. Exactly what you want.
- lab_notes_tom rated it 5/5 - Consistent improvement over 6 weeks: Added B7-33 to my protocol about 6 weeks ago and it has earned its place. The benefits became noticeable around week 2-3 and have been consistent since. What I appreciate about this compound is the predictability. It does what the research suggests it should do, at roughly the timeline you would expect. No surprises, no dramatic swings, just steady improvement. No notable side effects to report at my dose. Sourcing is always the challenge with research compounds, insist on third-party testing. Storage and reconstitution per standard protocols. Plan to continue.
- morning_pin_maya rated it 5/5 - Genuinely effective after 2 months: Been using B7-33 for about 2 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
- titration_tara rated it 4/5 - Solid compound with real results: Been using B7-33 for about 2 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
Compare B7-33
Research and educational reference only. Not medical advice.