Approved by at least one major regulator for a defined indication, with published human pharmacokinetics and a prescribing label. Well-characterised does not mean risk-free, read the label warnings.
Per the FDA label, after an oral solution containing radiolabelled drug, plasma radioactivity declined with mean half-lives of 27 hours (300 mg) and 20 hours (450 mg). These are plasma RADIOACTIVITY half-lives, not necessarily intact-drug half-lives. Only ~6% of an oral dose is absorbed and reaches systemic circulation; most is excreted in faeces as unchanged drug. Molecular weight is reported on the label as a 4,000-6,000 Da range because the compound is polydisperse, it is left blank here rather than collapsed to a single fabricated number.
FDA label: 300 mg/day taken as one 100 mg capsule orally three times daily. 100 mg per administration = 100,000 mcg. A fixed label dose, not a range.
Reconstituted: Capsules: store at controlled room temperature 15-30°C.
No boxed warning, but a serious warning applies. RETINAL PIGMENTARY CHANGES: pigmentary maculopathy has been identified with long-term use. Most cases occurred after 3 years or longer, though shorter durations are reported; cumulative dose appears to be a risk factor. Symptoms include difficulty reading and slow adjustment to low light. These changes MAY BE IRREVERSIBLE AND MAY PROGRESS EVEN AFTER STOPPING. The label directs a baseline retinal exam (OCT and autofluorescence) for all patients within six months of starting and periodically thereafter, with follow-up continuing after cessation. BLEEDING: a weak anticoagulant (1/15 the activity of heparin), rectal haemorrhage was reported in 6.3% of patients at 300 mg/day; evaluate patients undergoing invasive procedures or taking anticoagulants, high-dose aspirin, or NSAIDs. ALOPECIA: began within the first 4 weeks in trials; 97% of cases were limited to a single scalp area. Most common adverse reactions: alopecia 4%, diarrhoea 4%, nausea 4%, headache 3%, rash 3%. Contraindicated in known hypersensitivity.