Peptide
PT-141
CAS189691-06-3
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH) and a melanocortin-receptor agonist, closely related to Melanotan II. Supplied as a lyophilized powder for in-vitro laboratory research. Not for human or veterinary use.
- Free US shipping on $149.99+
- Ships the same business day
- Tracked shipping
Complete your order
Bacteriostatic Water
$9.99
needed to reconstitute
SSL Secure
Ships from USA
Same-Day Dispatch
- Supplied as
- Lyophilized powder in a sealed vial. Bacteriostatic water sold separately.
- Storage
- 2–8 °C refrigerated, or −20 °C for long-term storage. Keep refrigerated after reconstitution.
- Intended use
- Laboratory research only (in vitro). Not for use in humans or animals.
- Delivery
- Dispatched the same business day; shipping calculated at checkout, free on orders of $149.99 or more. US addresses only.
At a glancePT-141
- Intended use
- Laboratory research use only (in vitro). Not for human or veterinary use.
- Form
- Lyophilized (freeze-dried) powder in a sealed vial
- Sizes
- 10mg
- Storage
- Sealed vial: 2–8 °C, or −20 °C for longer storage. Keep dry and away from light.
- Shipping
- Ships the same business day when ordered by 3 PM ET (Mon–Sat), with tracking.
Terms on this page
- COA (Certificate of Analysis): the lab's test report for one batch and size.
- HPLC (high-performance liquid chromatography): the lab test that measures purity.
- Mass spectrometry (MS): a lab test that checks the molecule's mass, to confirm identity.
- Lyophilized: freeze-dried, for a stable powder.
— Product Overview
Description
PT-141 is a cyclic peptide of seven residues. In the sequence shown in the Specifications box, the N-terminal norleucine (Nle, a non-standard amino acid) is acetylated, the phenylalanine is the D-isomer, and the six residues from aspartic acid to lysine form a ring closed by an amide (lactam) bond between the Asp and Lys side chains. The chain ends in a free carboxylic acid.
That C-terminal acid is the only structural difference from Melanotan II, which has the same ring but ends in an amide, and it is why PT-141 is about 1 g/mol heavier. See Melanotan II vs PT-141.
The one size offered is PT-141 10mg, freeze-dried (lyophilized) in a sealed vial. Store vials away from light and divide any reconstituted solution into aliquots before freezing to avoid thawing and refreezing it repeatedly.
For research use only. Not for use in humans or animals.
— Data sheet
Specifications
PT-141Research use only
- CAS number
- 189691-06-3
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- Sequence
- Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
- Vial size
- 10mg
Formula and molecular weight: PubChem (CID 9941379), for the CAS number shown (the free peptide, not a salt form). For laboratory research use only. Not for human or veterinary use.
Research & comparisons
Melanocortin Peptides in Research: Melanotan II, PT-141 and KPV
Read →
Research article · Oct 2026
PT-141 (Bremelanotide): Mechanism of Action and Research Applications
Read →
Research article · Jul 2026
Melanotan II vs PT-141
Compare →
Head-to-head comparison
Reconstitution calculator
Open →
Preset for PT-141
Frequently Asked Questions
What is PT-141?
PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH) and a melanocortin-receptor agonist, closely related to Melanotan II.
What is it used for?
It is sold for in-vitro laboratory research only. It is not for use in humans or animals and is not intended to diagnose, treat, cure or prevent any disease.
How is PT-141 different from Melanotan II?
The two cyclic peptides share the same ring sequence; PT-141 ends in a free acid, Melanotan II in an amide.
How is it supplied?
As a lyophilized (freeze-dried) powder in a sealed vial. Bacteriostatic water is sold separately.
How should it be stored?
Store the sealed vial at 2–8 °C, or at −20 °C for long-term storage. Keep reconstituted solutions refrigerated.
Is this product for human use?
No. It is sold strictly for laboratory research use only and is not for human or veterinary use.
Where is the COA for PT-141?
Published lab reports are listed on the COAs page; the report for this product is added there when it is published.
When will my order ship?
Orders placed by 3 PM ET, Monday to Saturday, ship the same business day with tracking. Options and prices are on the Shipping Policy page.
Customer Reviews
Be the first to review PT-141.
Share your experience
Sign in or create an account to write a review. Reviews come from verified purchases to keep things authentic.
Bought this recently? Our "How was your order?" email carries a one-click review link for each product — no account needed.
Related Products
PT-141