Mots-c increases my baseline energy and aerobic capacity modestly. My problem with it is I’d always get itchy welts that would last many days. Switching to intra muscular instead of subway helped with that but it was clear my body didn’t like it. I got small hives the last time I used it and decided to call it quits, this is apparently pretty common with it so I’d recommend keeping liquid Benadryl on hand just to be safe.
Injectable carnitine I also like and am a fan of, I’ve lost weight on it and made workouts feel easier but it’s problem is your body adapts quickly to it and then there’s no point in taking it. I’ve cycled it a few times and that’s always my experience. I got 2 weeks, then 1 week and now it works for a few days if that. Also PIP depending on where you buy it from. Injectify in Canada I liked.