orlistat Research Reference

Catalog classification, reference sizes, lab math links, and source-backed data. Educational use only — not medical advice.

Researched for: PepTools vendor-neutral scientific reference catalog

anti-obesity agent; intestinal lipase inhibitor compound Reference approved

Also known as: tetrahydrolipstatin, (-)-tetrahydrolipstatin, Ro 18-0647/002, Xenical, CAS 96829-58-2

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Quick Facts

Reference Sizes

27 mg chewable tablet, 60 mg capsule, 120 mg capsule

Components

orlistat

Storage

For the labeled 120 mg capsule product: store at 25 °C (77 °F), with permitted excursions to 15–30 °C (59–86 °F), and keep the bottle tightly closed.

Solubility

Practically insoluble in water; freely soluble in chloroform; very soluble in methanol and ethanol.

Catalog Description

Orlistat is a synthetic beta-lactone derivative and reversible inhibitor of gastric and pancreatic lipases. It forms a covalent bond with the active serine residue of these enzymes, limiting the conversion of dietary triglycerides into absorbable free fatty acids and monoglycerides. It is classified as an intestinal lipase inhibitor and anti-obesity agent.

Catalog descriptions reflect research context only. Not a medical claim or treatment recommendation.

Research Profile

Half-Life

Approximately 1–2 hours for absorbed orlistat, based on limited pharmacokinetic data. Reported metabolite half-lives are approximately 3 hours for M1 and 13.5 hours for M3.

Onset

Pharmacodynamic effect, measured by fecal-fat excretion, is reported within 24–48 hours after dosing.

Administration Routes (Research)

oral

Reported Research Effects

Reversible inhibition of gastric and pancreatic lipases
Reduced hydrolysis and absorption of dietary triglycerides
Approximately 30% inhibition of dietary fat absorption at the labeled 120 mg three-times-daily regimen
Fecal-fat effect reported within 24–48 hours after dosing

Data source: Primary literature, regulator records, trial registries, and identity-specific evidence search

Reflects preclinical/research literature context only. Not a medical claim, dosing instruction, or treatment recommendation.

Research Notes

Authoritative product labeling describes a 120 mg oral capsule regimen administered three times daily with fat-containing main meals, during or up to 1 hour after a meal. European Medicines Agency product information identifies 60 mg capsules and 27 mg chewable tablets in addition to 120 mg capsules. These are neutral reference details from approved product information and are not individualized dosing guidance.

Supplementary research context only. Not medical advice or a treatment recommendation.

Registry Identifiers

CAS: 96829-58-2; PubChem CID: 3034010; ChEBI: CHEBI:94686; UNII: 95M8R751W8; molecular formula: C29H53NO5; molecular weight: 495.7 g/mol; IUPAC name: [(2S)-1-[(2S,3S)-3-hexyl-4-oxooxetan-2-yl]tridecan-2-yl] (2S)-2-formamido-4-methylpentanoate; InChIKey: AHLBNYSZXLDEJQ-FWEHEUNISA-N

Source-Backed Observations

Systemic exposure to intact orlistat is minimal at therapeutic doses. The majority of administered radioactivity is eliminated in feces, predominantly as unchanged orlistat; renal excretion is a minor route.

Reflects published research. Educational reference — not a recommendation for use.

Sources

ORLISTAT capsule: official prescribing information
https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=f81dfaeb-46d5-47ce-9ef6-19259f5ac61c&version=7 (accessed 2026-09-12)

XENICAL (orlistat) Capsules: FDA-approved labeling
https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/020766s038lbl.pdf (accessed 2026-09-12)

Orlistat referral: authorised strengths and safety information
https://www.ema.europa.eu/en/medicines/human/referrals/orlistat (accessed 2026-09-12)

Alli (orlistat) European public assessment report product information
https://www.ema.europa.eu/en/documents/product-information/alli-epar-product-information_en.pdf (accessed 2026-09-12)

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Research Use Only. All content is for educational and research reference only. Not medical advice, a treatment recommendation, or guidance on human use. Compounds are not FDA-approved drugs unless specifically noted.