ART27.13 Research

[designgears]

AI generated breakdown, because I'm lazy.

ART27.13 + semaglutide: new mouse data shows doubled weight loss, mostly fat

Saw this come out a few days ago and figured people here would find it interesting, especially anyone on sema or tirz worried about muscle loss.

What it is

ART27.13 is an oral, once-a-day pill, not a peptide. It's a cannabinoid receptor agonist (CB1/CB2) originally developed by AstraZeneca and now owned by a small biotech called Artelo. It's designed to stay mostly out of the brain, so no high. It's been through 7+ human trials with around 300 people and is currently in Phase 2 for cancer patients who are losing weight and muscle.

How the GLP-1 angle started

Back in March, Artelo started testing it as a muscle-protecting add-on for GLP-1 users. In their cancer trial, patients on the top dose gained about 6% body weight over 12 weeks while placebo lost about 5%, with improvements in lean mass and activity too.

The new results (Sept 16, obese mice, 4 weeks)

• ART27.13 alone: ~20% weight loss, basically matching semaglutide
• ART27.13 + sema: ~40% weight loss, double either one alone, bringing the mice down to normal-weight levels
• About 80% of the weight lost was fat with ART27.13, compared to about 70% with sema alone
• Zero effect in lean mice, so it only worked in obese animals
• Food intake dropped at first then came back to normal, but the weight stayed off
• Liver, cholesterol and blood sugar markers improved, best in the combo group
• This was a repeat of an earlier pilot study that showed the same combo effect

Why it's surprising

For 20+ years the thinking was that you had to block CB1 to lose weight. That's what rimonabant did, and it got pulled over depression side effects. This drug does the opposite and activates the receptors, just mostly outside the brain. The company's theory is that it acts like a metabolic regulator: it helps people who are wasting away gain weight and helps obese bodies lose it. The combo result also suggests it works through a different pathway than GLP-1s, which would explain why the effects stacked.

Where it stands

It's mouse data only, and just 4 weeks. There's no human data yet for obesity or for combining it with a GLP-1, and it's not approved for anything. Artelo is a small company and says it's looking for a pharma partner to take this further, so any human GLP-1 combo trial is probably a ways off. The cancer Phase 2 results are still pending and should give more human data on the lean mass side.

Sources: Artelo press releases from March 25 and Sept 16, 2026.