Is Semaglutide with B12 legal in the United Kingdom?

A compounded premix in which the B12 dose is decided by the semaglutide dose rather than by anyone's B12 level. Cyanocobalamin sits at 0.5 mg/mL across strengths while semaglutide is 1 or 5 mg/mL, so the same product delivers five times more B12 per milligram of semaglutide on one strength than on the other. No trial has tested the combination, and no trial supports the reason it is added.

Compounding pharmacies pair semaglutide with cyanocobalamin and the stated reasons are that B12 helps with the nausea and with the fatigue people report on a GLP-1. Neither claim has a trial behind it.

Mechanism: Semaglutide is a GLP-1 receptor agonist that slows gastric emptying and reduces appetite through central and peripheral GLP-1 signalling. Cyanocobalamin is a vitamin B12 form used to correct deficiency, and its physiological effects in a person who is not deficient are minimal.

Regulatory history: Not an approved product. Compounded preparations are not FDA approved and are not reviewed for safety, effectiveness or quality, and FDA has stated concerns about unapproved GLP-1 products sold for weight loss.

Licenses medicines for the UK market. A compound without a marketing authorisation is an unlicensed medicine, which can only lawfully be supplied for human use through a prescriber under the specials scheme, not sold as a research product.

The classification above is the The Longevity Archive reading of Medicines and Healthcare products Regulatory Agency listings for Semaglutide with B12 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.