Semaglutide

Definition

Semaglutide is a GLP-1 receptor agonist, a modified analogue of the gut hormone glucagon-like peptide-1 engineered for once-weekly subcutaneous dosing; an oral formulation is marketed separately. It is approved in the United States for type 2 diabetes and, at a higher dose, for chronic weight management.

The molecule slows gastric emptying, augments glucose-dependent insulin secretion, and acts on central appetite circuits; the weight effect is a drug effect, not a property of the injection route.

Evidence

In the pivotal STEP 1 trial, 1,961 adults with overweight or obesity received once-weekly semaglutide 2.4 mg or placebo; mean weight change at week 68 was −14.9 percent against −2.4 percent with placebo, and half of treated participants lost 15 percent or more ^[1].

The evidence base is unusually deep for this index; the open questions concern durability after discontinuation and long-term use outside trial conditions rather than whether the drug works.

Lawful access

The approved products are the lawful supply route. Mass compounding ended after the FDA declared the shortage resolved; in April 2026 the agency proposed excluding semaglutide from the 503B bulks list, and the remaining 503A path requires a prescriber to document a clinical need an approved product cannot meet — a lower price does not qualify ^[2].

Telehealth programs in the supply panel provide prescriber-led GLP-1 treatment; the specific molecule and formulation offered vary by provider and should be confirmed on the provider's own site.

Related molecules

Semaglutide shares its class and its regulatory shape with tirzepatide; the GLP-1 receptor agonists page compares the class, and the approved status page lists every approved molecule in this index.