Do GLP-1s raise your heart rate?

This is one of the more measurable and under-discussed effects of GLP-1 drugs, and Attia has covered it in a dedicated explainer. The finding: resting heart rate rises by a consistent 8-12 bpm, and heart-rate variability (HRV) - a marker of autonomic balance and recovery - gets compressed.

The mechanism is likely vagus-nerve mediated rather than a sign of cardiovascular damage, and the effect is reversible: both resting heart rate and HRV typically normalize within about a month of discontinuing the drug. HRV specialist Joel Jamieson (via Attia) independently reports the same 8-12 bpm increase and HRV compression, and raises the longer-term question of what sustained sympathetic "overdrive" costs someone using the drug for years.

Why it matters in practice: if you wear a recovery tracker, expect your readiness/HRV scores to look worse on a GLP-1 - that is the drug, not necessarily your fitness. And for someone using a GLP-1 cosmetically (to lose a modest amount of weight) rather than to treat obesity or diabetes, the resting-heart-rate cost is a real part of the trade-off worth discussing with a physician. Note this is distinct from the drugs' established cardiovascular-event benefit in higher-risk patients - heart rate up in the short term, major cardiac events down over the long term are not contradictory.