AT7687vsLipo-C

AT7687 is a long-acting GIP receptor antagonist designed to reduce fat storage rather than suppress appetite — a fundamentally different mechanism from every other obesity drug currently on the market or in late-stage development. The rationale is grounded in human genetics: loss-of-function variants in the GIP receptor are associated with lower body mass index and reduced cardiometabolic risk, suggesting that pharmacologically blocking GIP signalling should reproduce these protective effects.

GIP (glucose-dependent insulinotropic polypeptide) normally functions as a fat-storage signal — released from intestinal K-cells in response to food intake, it instructs adipose tissue to take up and store circulating fatty acids. By blocking the GIP receptor specifically on adipocytes, AT7687 prevents this fat-storage signal from being transmitted, leading to reduced lipid uptake into fat cells and a metabolic shift favouring fat oxidation in muscle and liver. Because the mechanism does not depend on suppressing hunger or slowing gastric emptying, the gastrointestinal side effects that limit GLP-1 drug tolerability are largely absent.

This mechanism is the conceptual mirror of MariTide (which combines GLP-1 agonism with GIP antagonism in a single molecule) — AT7687 isolates the GIP-antagonist component to test whether it can produce meaningful weight loss alone or in future combination with GLP-1 agonists. Antag Therapeutics' first-in-human Phase 1 results in 2026 showed acceptable tolerability with mild GI symptoms, plus reductions in LDL cholesterol and resting heart rate — early signals consistent with the predicted cardiometabolic benefit profile. Phase 2 trials are expected to define the magnitude of weight loss achievable in obese patients.

Lipo-C is a multi-component lipotropic formulation where each ingredient targets a different aspect of fat metabolism. The MIC complex (methionine, inositol, choline) forms the core. Methionine is an essential amino acid that serves as a methyl donor and precursor to S-adenosyl methionine (SAM), which is required for the methylation of phospholipids in the liver — a process critical for packaging and exporting triglycerides as VLDL particles. Without adequate methionine, fat accumulates in hepatocytes.

Inositol, specifically myo-inositol, functions as a second messenger in insulin signaling pathways and is involved in phospholipid synthesis. It enhances insulin sensitivity at the cellular level and plays a role in serotonin receptor function, which may help regulate appetite and mood during caloric restriction. Choline is the precursor to phosphatidylcholine, the primary phospholipid component of cell membranes and lipoprotein particles. Choline deficiency directly causes hepatic steatosis (fatty liver) because the liver cannot package and export triglycerides without sufficient phosphatidylcholine.

The formulation is typically augmented with vitamin B12 (cyanocobalamin or methylcobalamin), which is a cofactor for methionine synthase and required for proper methylation cycle function, and L-carnitine, which transports long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Together, the components support hepatic fat processing, mitochondrial fat burning, and the metabolic methylation pathways that connect them. The clinical evidence for MIC injections specifically is limited, though the biochemical rationale for each individual component in fat metabolism is well-established.