A1C increased

[wkndworrier]

I've been on Retatrutide for about 2 months at 4mg per week for the last month and am generally pleased with the fat loss and body composition changes (consistently about 1lb per week without much impact to strength).

I had some labs drawn and was surprised to see that my A1C had risen to 5.4 from 5.1 - which was the result of a few months on Tirzepitide, but only taking 1.5mg per week. My baseline has been 5.4 - 5.5 for the last decade, pre any GLP1 drug. My fasting glucose was 87, which is definitely lower than my typical baseline of mid-high 90s. Does the glucagon receptor agonist slightly raise blood sugar?

 

[diogenes]

Relative to tirzepatide, yes. Studies find A1C falls more on tirz than reta.

Glucagon mobilizes glycogen into glucose, so reta can increase blood glucose, hence higher A1C. But for most people on reta, the A1C decrease from reduced food (esp carb) intake means A1C falls overall. That seems not to be the case for you, but that isn't necessarily bad.

A1C 5.5 is normal, not a sign of metabolic problems. And small changes in A1C below 5.7 aren't necessarily instructive. You might ask your doc to measure your insulin sensitivity. That is a more robust measure of metabolic health than 0.3 points of A1C variation within normal range.

Visceral fat is itself harmful to metabolism. If your waist is shrinking to a healthier width, that is a good sign for your metabolism. Trust the process.