Minoxidil
A small-molecule drug applied to the scalp as an over-the-counter hair-regrowth treatment, and taken orally as a prescription blood-pressure medicine.
Minoxidil Biological Classification
Investigated within physiological and chemical models.
What kind of compound
Small molecule
Small-molecule vasodilator and ATP-sensitive potassium-channel opener, supplied as a topical solution or foam and as oral tablets.
Human testing on file
0human records
0 animal · 1 total indexed. Approved drug product in the United States.
Regulatory position
FDA-approved as an over-the-counter topical for androgenetic alopecia; oral tablets are approved for hypertension, not hair loss.
Studied for
Approved topical hair-regrowth treatment
Reviewed 13 November 2026
Known safety concerns in this file
- Topical products can cause scalp irritation and unwanted facial hair growth.
- Oral minoxidil is a vasodilator with cardiovascular effects and is not a casual supplement.
- The approved label lists warnings and side effects; this is not a complete safety profile.
Commonly compared with
- Finasteride — Approved oral treatment for men, different mechanism.
- Dutasteride — Not FDA-approved for hair loss.
- GHK-Cu — Cosmetic copper peptide with no approval.
What is Minoxidil?
A small-molecule drug applied to the scalp as an over-the-counter hair-regrowth treatment, and taken orally as a prescription blood-pressure medicine. A small-molecule drug with two distinct regulatory identities: an over-the-counter topical hair-regrowth product and a prescription oral antihypertensive. The topical route is the only FDA-approved form for androgenetic alopecia.
Why are people interested in it?
It is one of only two FDA-approved medical treatments for androgenetic alopecia, so it is the benchmark against which hair-loss claims are measured.
Primary Research Categories
- Hair-growth drugs
- Small-molecule drugs
- Approved drug substances
How does it work in the body?
Opens ATP-sensitive potassium channels and dilates blood vessels; it also prolongs the growth phase of the hair cycle. The precise reason it grows hair is still debated.
Biological Pathway Overview
Minoxidil Receptor & Target Interactions
This compound is evaluated in scientific research for its interactions with target cellular receptors and signaling cascades. Consult the evidence section below for specific peer-reviewed papers.
Potassium channels
Named in the published mechanism discussion for this compound.
Vasodilation
Named in the published mechanism discussion for this compound.
Anagen prolongation
Named in the published mechanism discussion for this compound.
Key Distinction: Approval applies to the specific indication and product on the label, not to every use of the molecule.
What has actually been demonstrated in humans?
Randomised trials and decades of clinical use support topical minoxidil for androgenetic alopecia in men and women. Oral low-dose use for hair loss is off-label.
Pharmaceutical Reality vs. Unregulated Research Chemicals
FDA-approved as an over-the-counter topical for androgenetic alopecia; oral tablets are approved for hypertension, not hair loss. Why some people respond and others do not.
What is still uncertain or unknown?
Why some people respond and others do not. Long-term maintenance after stopping. Whether low-dose oral minoxidil has an acceptable long-term risk profile for cosmetic use.
Research at a Glance
Open the full evidence file (1 records)1 record in this file
- REGULATORY1
Publication span: 2006
What Has Actually Been Studied
- NDA 021812 — topical minoxidil foam for male androgenetic alopecia: medical review (FDA new drug application review, 2006) — Regulatory review of an over-the-counter topical product.
What is Still Unknown
What we know
Editorial reading of the records below, labelled as Therapept analysis. How records are built
What remains uncertain
Preparation and Handling
Lyophilized peptides ship as freeze-dried powders; whatever happens next involves diluents, concentrations and storage conditions that are compound- and product-specific.
United States Regulatory Status
FDA-approved drug substance
Approved Indication: Topical 2% and 5% products are marketed in the United States for androgenetic alopecia in men and women. Oral minoxidil tablets are approved for hypertension; low-dose oral minoxidil for hair loss is off-label.
- Topical minoxidil for androgenetic alopecia has been available over the counter in the United States since 1996, in 2% and 5% strengths.
- Oral minoxidil is an FDA-approved prescription antihypertensive. Low-dose oral use for hair loss is off-label and is not an approved indication.
- FDA-approved labelling for topical minoxidil is specific about the studied scalp area; it is not a general hair-growth licence.
Technical Chemical SpecificationsClick to view CAS, sequence, and molecular formulas
- Molecular weight
- 209.25 g/mol
- Sequence length
- Not recorded
- CAS number
- 38304-91-5
- PubChem CID
- 4201
- Compound class
- Small-molecule vasodilator and ATP-sensitive potassium-channel opener, supplied as a topical solution or foam and as oral tablets
- Sequence
- Unknown / Unassigned
- Molecular formula
- C9H15N5O
- Molecular weight
- 209.25 g/mol
- CAS number
- 38304-91-5
- PubChem CID
- 4201
Sources
Last reviewed 13 November 2026 · Compiled by Therapept Editorial · How these records are built