In humans, intravenous administration of S-adenosylmethionine (100 mg, 500 mg, and 0.5 mg/kg of body weight) directly into the bloodstream has a half-life of approximately 80 to 100 minutes.[1][2] Furthermore, there are detectable increases in S-adenosylmethionine concentrations in the blood and the cerebrospinal fluid after oral, intravenous, and intramuscular administration, suggesting that S-adenosylmethionine crosses the blood-brain barrier.[3]
In humans, intramuscular administration of S-adenosylmethionine (0.5 mg/kg of body weight) shows approximately 80–90% bioavailability — i.e., 80–90% of S-adenosylmethionine injected into a muscle appears in the blood.[1] However, when orally administered in humans, the bioavailability of S-adenosylmethionine is poorer,[3][4] as low as 2–3% in some studies.[5] However, some studies show that enteric-coated capsules of S-adenosylmethionine, which are protected from degradation by stomach acid, have improved bioavailability in humans when compared to uncoated S-adenosylmethionine.[6][7] Novel formulations such as phytate salts[8] and solid lipid nanoparticles[9] have further improved oral bioavailability in rodents, but these formulations remain to be tested in humans.
References
- ^Stramentinoli G, Catto EPharmacokinetic studies of S-adenosyl-L-methionine (SAMe) in several animal species.Pharmacol Res Commun.(1976 Apr)
- ^Giulidori P, Cortellaro M, Moreo G, Stramentinoli GPharmacokinetics of S-adenosyl-L-methionine in healthy volunteers.Eur J Clin Pharmacol.(1984)
- ^Friedel HA, Goa KL, Benfield PS-adenosyl-L-methionine. A review of its pharmacological properties and therapeutic potential in liver dysfunction and affective disorders in relation to its physiological role in cell metabolism.Drugs.(1989 Sep)
- ^Gören JL, Stoll AL, Damico KE, Sarmiento IA, Cohen BMBioavailability and lack of toxicity of S-adenosyl-L-methionine (SAMe) in humansPharmacotherapy.(2004 Nov)
- ^Yang J, He Y, Du YX, Tang LL, Wang GJ, Fawcett JPPharmacokinetic properties of S-adenosylmethionine after oral and intravenous administration of its tosylate disulfate salt: a multiple-dose, open-label, parallel-group study in healthy Chinese volunteers.Clin Ther.(2009 Feb)
- ^G StramentinoliPharmacologic aspects of S-adenosylmethionine. Pharmacokinetics and pharmacodynamicsAm J Med.(1987 Nov 20)
- ^Beth R Cameron, Ludvina Ferreira, I David MacDonaldPharmacokinetic study of a novel oral formulation of S-adenosylmethionine (MSI-195) in healthy subjects: dose escalation, food effect and comparison to a commercial nutritional supplement productBMC Pharmacol Toxicol.(2020 Dec 14)
- ^Antonio Francioso, Sergio Fanelli, Maria d'Erme, Eugenio Lendaro, Niccolò Miraglia, Mario Fontana, Rosaria A Cavallaro, Luciana MoscaPharmacokinetic properties of a novel formulation of S-adenosyl-L-methionine phytateAmino Acids.(2021 Oct)
- ^Gulin Amasya, Ahmet Dogan Ergin, Ozge Erkan Cakirci, Arif Tanju Ozçelikay, Zerrin Sezgin Bayindir, Nilufer YukselA study to enhance the oral bioavailability of s-adenosyl-l-methionine (SAMe): SLN and SLN nanocomposite particlesChem Phys Lipids.(2021 Jul)