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№ 046

B7-33

A compound aimed at reducing scar-tissue buildup (fibrosis). A single-chain peptide derivative of relaxin, designed to retain anti-fibrotic activity without the cardiovascular side profile of full relaxin. Pre-clinical / early human research.

Healing
Evidence: Anecdotal

B7-33: A compound aimed at reducing scar-tissue buildup (fibrosis). A single-chain peptide derivative of relaxin, designed to retain anti-fibrotic activity without the cardiovascular side profile of full relaxin. Pre-clinical / early human research. B7-33 is a single-chain fragment of relaxin designed to keep the anti-fibrotic effect (good for hearts, kidneys, lungs) without dropping blood pressure (the side effect of full relaxin).

FDA ⓘ
Not approved
WADA
Not banned
Typical dose
No human protocol exists
Half-life ⓘ
~6 min in-vitro native; ~60 min lipidated (no in-vivo PK)
Route ⓘ
Subcutaneous
Schedule
Once daily in animal models
In plain English

B7-33 is a single-chain fragment of relaxin designed to keep the anti-fibrotic effect (good for hearts, kidneys, lungs) without dropping blood pressure (the side effect of full relaxin). Pre-clinical only. Don't use this without medical oversight.

Status & legalityWhat do these mean? →
Natty? ⓘ
Not natty
FDA ⓘ
Not approved

Not FDA approved. Pre-clinical research compound.

Compounding ⓘ
Not classified

Not formally categorized in the FDA bulks lists.

WADA ⓘ
Not listed
Prescribed ⓘ

Not prescribed in conventional medicine.

Who it's for

  • →Researchers studying fibrotic disease pathways
  • →Cardiovascular-research context only
  • →Educational reference, not for community use

What to expect

  1. Week 1

    No documented human user reports of acute effects.

  2. Week 4

    Pre-clinical models show anti-fibrotic markers shifting around here.

  3. Week 8

    No long term human data exists.

Looking at B7-33? Your next 3 steps

  1. 1Work out your exact dose

    Vial size + BAC water turns into the exact units to draw for B7-33.

    Open calculator →
  2. 2See what to stack & monitor

    The companion supplements and the bloodwork worth tracking on this kind of protocol.

    Bloodwork guide →
  3. 3Save it & ask the Coach

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How it works (mechanism)

Single-chain peptide derivative of relaxin that retains binding to relaxin receptor RXFP1 with anti-fibrotic signaling, but lacks the cardiovascular receptor crosstalk responsible for relaxin's hypotensive effect.

Dosing protocol

Members only

Stacks well with

Members only

Side effects

01Limited human data
02Theoretical hypotensive effect
03Injection-site reaction

When NOT to use

  • ⚠Hypotension or unstable cardiovascular status
  • ⚠Pregnancy / nursing
  • ⚠Anyone risk-averse to pre-clinical-only data

Common mistakes

  • • Treating community-vendor B7-33 as research grade clinical material
  • • Running it without published human safety data
  • • Stacking it with anything else
Free, no account needed

New to B7-33? Grab the starter checklist.

Drop your email and we'll send the one-page first-cycle starter checklist, plus a heads-up if B7-33 changes legal status. No account needed.

No spam. No selling your email. Just the checklist and the occasional reclassification alert.

AI Coach, live sample
Members only
is 250mcg of bpc enough for a knee injury?
For a knee, 250 mcg sub-q daily is the standard working dose and a solid place to start. The trick with BPC is consistency, give it weeks, not days. Inject close to the joint, run it 4-6 weeks, and don't drop below 200 mcg, it tends to stop cracking the threshold reliably down there. If it hasn't moved at all by week 3, that's when adding TB-500 earns its place.
how much bac water for a 10mg reta vial?
3 mL is the standard play for a 10 mg reta vial. That's 3,333 mcg/mL, clean unit math across the titration: 2 mg = 60 units, 4 mg = 120 units, 6 mg = 180 units on a 100-unit insulin syringe. Run 2 mL instead if you want fewer, more concentrated shots (5,000 mcg/mL, so 2 mg = 40 units). Since most people titrate up over ~12 weeks, 3 mL keeps the numbers cleanest.
what should i track on bloodwork for tirzepatide?
Lipid panel, ALT/AST (liver enzymes), and an A1C, baseline before you start then every 3 months. If you've got metabolic-syndrome history, add fasting glucose and insulin so you can actually watch insulin sensitivity improve. You don't need a big hormone panel for a GLP-1.

Ask the Coach anything about B7-33 or your own stack. This is it working.

Trained only on Pepdex content. Does the dose math, flags interactions, knows your stack. Won't push vendors, won't pretend to be a doctor.

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Frequently asked

What is B7-33?+
B7-33 is a single-chain fragment of relaxin designed to keep the anti-fibrotic effect (good for hearts, kidneys, lungs) without dropping blood pressure (the side effect of full relaxin). Pre-clinical only. Don't use this without medical oversight.
Is B7-33 FDA approved?+
Not FDA approved. Pre-clinical research compound.
Is B7-33 legal?+
B7-33 is not FDA-approved. It is sold by compounding pharmacies (with a prescription) and as "research only" by peptide vendors. Possession is generally not criminalized but distribution without authorization may be. Verify local laws.
Is B7-33 banned by WADA?+
B7-33 is not currently on the WADA prohibited list.
Are you still natty after taking B7-33?+
No. B7-33 is a performance-enhancing peptide and would disqualify a strict natty claim.
Do doctors prescribe B7-33?+
Not prescribed in conventional medicine.
What's the typical dose of B7-33?+
No human protocol exists. Animal-model dosing is per-kg and not directly translatable.
What are the side effects of B7-33?+
Common side effects include: Limited human data; Theoretical hypotensive effect; Injection-site reaction. Less common effects and full safety details are on the entry page.
How long until B7-33 starts working?+
No documented human user reports of acute effects.
What can you stack with B7-33?+
Common pairings: Not stacked, too experimental. Full stacking protocol and timing on the entry page.
Where do people get B7-33?+
B7-33 is most commonly sold by research-only peptide vendors and by compounding pharmacies (the latter requires a prescription). Pepdex is not a vendor, see /coa for how to verify a Certificate of Analysis before buying from any source, and /guides/scam-vendor-spotting for vendor red flags.

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