Lixisenatide

Lixisenatide is a short-acting GLP-1 receptor agonist approved for type 2 diabetes, sold as Adlyxin in the US and Lyxumia in Europe and included in the fixed-ratio insulin combination Soliqua/Suliqua (iGlarLixi). It is a synthetic analogue of exendin-4, the same lizard-derived peptide behind exenatide, modified with six lysine residues at the C-terminus. It is an FDA-approved prescription drug, not a research chemical.

It is a minor player. Semaglutide and tirzepatide are long-acting, once-weekly agonists that drive roughly 15-21% weight reduction, while lixisenatide is once-daily, short-acting, and produces only modest weight change (about 2-3 kg). Its niche is blunting post-meal glucose spikes rather than sustained appetite suppression. Sanofi discontinued Adlyxin in the US market in 2023 for commercial reasons (not safety), and it has been largely sidelined by the weekly incretins.

Its half-life is only about 3 hours, so plasma levels rise and fall around a single daily injection taken before a meal. This produces a pronounced, transient slowing of gastric emptying that flattens the post-meal glucose curve, with comparatively little effect on fasting glucose. Long-acting agents like semaglutide instead maintain steady receptor activation and lower fasting glucose more strongly.

ELIXA (Pfeffer et al., 2015) enrolled 6,068 people with type 2 diabetes and a recent acute coronary syndrome and found that lixisenatide neither increased nor decreased major cardiovascular events versus placebo. It was the first completed cardiovascular outcomes trial for any GLP-1 receptor agonist and established cardiovascular safety, though without the risk reduction later seen with semaglutide.

The LixiPark phase 2 trial (Meissner et al., 2024) randomized 156 people with early Parkinson's to daily lixisenatide or placebo for 12 months. Motor scores stayed roughly stable on lixisenatide but worsened on placebo, suggesting a modest slowing of motor progression. Nausea (46%) and vomiting (13%) were common. It is an early signal, not an approved use, and larger trials are needed to confirm it.

Dosing starts at 10mcg once daily for 14 days, then increases to the 20mcg maintenance dose, injected within one hour before the first meal of the day. It ships as a ready-to-use prefilled pen with no reconstitution. Keep it refrigerated at 2-8°C before first use, then below 30°C for up to 14 days, and never freeze it.