Side-effects of GLP-1 Inhibitors
Over the last couple of months, I have been experimenting on and off with Tirzepatide, a second generation GLP-1 inhibitor drug after Semiglutide. These drugs are great. These are extremely effective weight loss medications that work by regulating appetite. Many people claim that they have low to no side-effects, and I'm happy for those people. However, I haven't been entirely so lucky. Below is a record of my experiences.
Timeline
October to November 2024
I first took it during October and November 2024. I began on the lowest dose of 2.5 mg and, due to a misunderstanding of what the doctor said, believed it was expected to increase the dosage regularly. The second month I went up to 5 mg and that was too much for me.
Due to pressure from my then-girlfriend and my own reconsideration for reasons that will be obvious when I list the side effects, I quit for a few months.
May to July 2025
As I write this, I am back on it now. This time I made a very deliberate choice to stay at the lowest dose of 2.5 mg and even then I don't reliably take it every week. Things have been progressing well and everyone has said I look better. The side effects aren't completely gone, but they are much more manageable.
Side-effects
Obviously most of these side-effects are consequences of the primary effect of eating much less, but they may not be the first things you think about when you approach the idea of taking an appetite suppressant. Be warned.
- Indigestion
- I'm not normally prone to indigestion but these drugs gave me regular cases. It was worst when I ate too much, but it also became a regular occurrence in the mornings even if I didn't overeat.
- Fatigue
- Something that is not appreciated enough about eating much less is you have less energy (duh!) This made it hard for me to keep up my routines at the gym. I lacked energy. and frequently took naps in the middle of the day. Fatigue was a common companion and on the higher 5 mg dose I felt like I lacked the energy for normal life.
- Muscle Loss
- Because my body was not getting enough fuel, I lost muscle mass much faster than I would have liked. In the worst month, I lost eight pounds and it was 50% muscle mass. This was partially due to a diet that happened to be light on protein that month and I was able to correct, but that was a serious blow to my ego. My goal is not just to lose weight, but to reach a certain body fat percentage. If I lose muscle as fast as I lose fat, the body fat percentage doesn't budge. I would end up with a skinny-fat body instead of the healthy body I want.
- Dampened Libido
- Something that tends to happen when you are tired all the time and not eating enough is that your body recognizes the reduced energy and turns off functions that aren't essential to survival, with sex drive being one of the biggest. It's very hard to build a serious romantic relationship without regular sex. I was frustrated and so was she.
Overall, I just wasn't having a good time with that first attempt. Things seem to be going okay on the second, but I'm watching closely.