Minoxidil

Minoxidil

Clinical data
Trade names	Rogaine
AHFS/Drugs.com	Monograph
Pregnancy category	C
Routes of administration	Oral / topical
ATC code	C02DC01 (WHO) D11AX01 (WHO)
Legal status
Legal status	UK: P (Pharmacy medicines) (for topical use, otherwise POM. Cannot be prescribed on the NHS)
Pharmacokinetic data
Metabolism	Primarily hepatic
Biological half-life	4.2 h
Excretion	renal
Identifiers
IUPAC name 6-(1-Piperidinyl)pyrimidine-2,4-diamine 3-oxide 6-(1-Piperidinyl)-2,4-pyrimidinediamine 3-oxide 2,4-pyrimidinediamine,6-(1-piperidinyl)-, 3-oxide
CAS Number	38304-91-5 Y
PubChem CID	4201
IUPHAR/BPS	4254
DrugBank	DB00350 N
ChemSpider	10438564 Y
UNII	5965120SH1
KEGG	D00418 N
ChEBI	CHEBI:6942 N
ChEMBL	CHEMBL802 N
PDB ligand	MXD (PDBe, RCSB PDB)
ECHA InfoCard	100.048.959
Chemical and physical data
Formula	C9H15N5O
Molar mass	209.251 g/mol
3D model (Jmol)	Interactive image
Melting point	248 °C (478 °F)
Solubility in water	<1 mg/mL (20 °C)
SMILES Nc1cc(nc(N)[n+]1[O-])N2CCCCC2
InChI InChI=1S/C9H15N5O/c10-7-6-8(12-9(11)14(7)15)13-4-2-1-3-5-13/h6H,1-5,10H2,(H2,11,12) N Key:ZFMITUMMTDLWHR-UHFFFAOYSA-N N
NY (what is this?)

Minoxidil is an antihypertensive vasodilator medication. It also slows hair loss and promotes hair regrowth in some people. It is available as a generic medication and over the counter for the treatment of androgenic alopecia, a form of hair loss, in men and women.

Minoxidil, applied topically, is widely used for the treatment of hair loss. It is effective in helping promote hair growth in both men and women with androgenic alopecia. About 40% of men experience hair regrowth after 3–6 months. Minoxidil must be used indefinitely for continued support of existing hair follicles and the maintenance of any experienced hair regrowth.

Its effect in people with alopecia areata is unclear.

Minoxidil is generally well tolerated, but common side effects include burning or irritation of the eye, itching, redness or irritation at the treated area, as well as unwanted hair growth elsewhere on the body. Exacerbation of hair loss/alopecia has been reported. Severe allergic reactions may include rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue, chest pain, dizziness, fainting, tachycardia, headache, sudden and unexplained weight gain, or swelling of the hands and feet. Temporary hair loss is a common side effect of minoxidil treatment. Manufacturers note that minoxidil-induced hair loss is a common side effect and describe the process as "shedding".

Alcohol and propylene glycol present in some topical preparations may dry the scalp, resulting in dandruff and contact dermatitis.

Side effects of oral minoxidil may include swelling of the face and extremities, rapid and irregular heartbeat, lightheadedness, cardiac lesions, and focal necrosis of the papillary muscle and subendocardial areas of the left ventricle. There have been cases of allergic reactions to minoxidil or the non-active ingredient propylene glycol, which is found in some topical minoxidil formulations. Pseudoacromegaly is an extremely rare side effect reported with large doses of oral minoxidil.