u/CodeEuphoric4326

There's a really interesting study that came out in Nature last month looking at genetic predictors of GLP-1 treatment response. The researchers identified a missense variant in the GLP1 receptor gene (called rs10305420) that was associated with about 0.76 kg (1.7 lbs) of extra weight loss per copy of the variant.

They also found genetic links to side effects. Variants near the GLP1 receptor gene were associated with nausea and vomiting, and a separate variant in the GIP receptor gene increased the risk of vomiting specifically in patients taking tirzepatide.

The authors were careful to say that genetics only explain about 25% of the variation in weight loss responses, and non-genetic factors like age, sex, and which drug you're on matter more. But it's still nice to have some kind of explanation for why I've always been a slower loser than some of my friends on the same meds.

The TRCA (Therapeutic Research Center of America) just published results from a survey of over 2,100 GLP-1 users (mostly tirzepatide and semaglutide) on immunogenicity reactions.

Key findings:

4.3% reported injection site reactions (redness, swelling, itching)

0.8% reported systemic allergic-type reactions

Reactions were mild in most cases (grade 1, not requiring treatment)

Higher rates of reactions were seen in patients with prior history of drug allergies

The authors noted that immunogenicity is a concern for long-term use, as higher antibody levels could potentially reduce efficacy over time. But anti-drug antibodies were detected in 5-10% of patients in clinical trials, with neutralizing antibodies in about 1% (though these didn't correlate with reduced efficacy in most cases).

common genetic variants that predict how much weight you'll lose on GLP-1s