B7-33_Dosage, benefits & legal status
Also known as relaxin B-chain analog, B7 33, single-chain relaxin
A single-chain piece of relaxin, built to keep the anti-scarring effect and drop the tumor risk.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is B7-33?
Plain language first. The technical label stays, but it never stands alone.Overview
A short piece of a hormone called relaxin, designed to keep its anti-scarring effect without the part linked to tumor growth. It has never been tested in a person.
A 26-residue single-chain derivative of the H2 relaxin B-chain, functioning as a biased RXFP1 agonist favouring pERK1/2 over cAMP signaling. Developed at the Florey Institute in 2016. Reported to promote MMP-2 expression and reverse fibrosis across multiple rodent organ models. In vitro serum half-life approximately 6 minutes.
What it's used for
Studied in animals for scarring in the heart, lungs and kidneys. Sold online for recovery and tissue repair on the strength of that animal work.
How does B7-33 work?
What it does in the body, and where.Relaxin does two things through the same receptor, and B7-33 was built to keep one of them.
- 01Relaxin activates RXFP1 through two routesOne route runs through cAMP and one through pERK1/2. The anti-scarring effect is attributed to the second.
- 02B7-33 leans toward one and away from the otherIt is described as a biased agonist, favouring the pERK pathway with much less cAMP activation. That bias is the entire design intention.
- 03The reason for the bias is a tumor concernStrong cAMP activation by full relaxin has been linked to tumor growth in long-term use, and to increased cardiac workload. Dropping that arm is the point of the molecule.
- 04It clears extremely fastSerum half-life is reported at around six minutes in laboratory testing, which is short even by peptide standards. Later work attaching a fatty acid extended it to around sixty minutes.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Reducing scarring in the heart after injury, in animal modelsEarly research
- Kidney and lung fibrosis, in animal modelsEarly research
- Widening blood vessels and improving blood flow, in animal modelsEarly research
The published record
Papers and trials about B7-33
6 papers tagged human · 5 not reviews or lab · 0 clinical trial publications
Furthest stage reached: No clinical trial on record
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count.
At a glance
Four things to know about B7-33
Evidence
Category
Healing and recovery
Common vial
10 mg
Half-life
About 6 minutes in serum
How much, and do you cycle it?
The range, and whether you take breaks.Research only, varies. No established pattern No range
No published human study establishes a schedule.
How long does it stay in the body?
The half-life, and where the figure comes from.About 6 minutes in serumpeer-reviewed
Measured in human serum in vitro rather than in a person. A fatty-acid conjugated version was reported to extend this to about 60 minutes. Neither figure is a human pharmacokinetic result.
Source: Reported in structure-activity work from the originating laboratory
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
B7-33 starts at $60.00 across 6 vendors, typically $7.00 – $13.20 per mg.
6 listings, last read Oct 10, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized B7-33 keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Who should avoid it
- Pregnancy or breastfeeding
- Any active cancer, since the parent hormone has a tumour-growth signal
- Any use, given no human trial exists
Stop and get help
- Any allergic reaction
- Any unexpected symptom
Common effects
- No human safety data exists.
- Everything known comes from cell work and animal models.
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is B7-33 approved?
And where the numbers on this page come from.No. B7-33 is not approved for any use, anywhere. It is sold labeled for laboratory research only, and there is no legal route to buy it for human use.
- Approval statusResearch only
- RouteUnder the skin (subcutaneous)
- Checked24 August 2026
- DoseFrom community reports. No regulator or trial established this dose.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesNone traced yet.
What has happened recently
We have not yet written a full regulatory note for this compound. The status above is current as of the date shown.
You can compare this against the whole library, or read how to check a seller.
What else is like B7-33?
Others in Healing and recovery, side by side.If you're weighing B7-33, it's worth reading Coremend blend (TB-500 / BPC-157 / KPV), Vesilute, and Cerebroprotein Hydrolysate in the same class.
A single-chain piece of relaxin, built to keep the anti-scarring effect and drop the tumor risk.
- Dose
- Research only
- How often
- Varies
A named healing triple that is the Wolverine blend with KPV added.
- Dose
- 0.25 up to 0.5 mg BPC-157 per day (the rest follows your ratio)
- How often
- Varies
A lab-made 2 amino acid peptide aimed at the bladder.
- Dose
- Research only
- How often
- Daily, in 10-20 day courses
A generic name for pig-brain peptide mixtures, sometimes including Cerebrolysin itself.
- Dose
- Given in the hospital as a course of daily infusions
- How often
- Hospital courses of daily infusions
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
No primary source has been traced for this compound yet. Treat everything on this page as unverified until one is. How we grade evidence
Beyond these, 11 records are indexed. Browse the records