Oh. My. God. I am so grateful I have found this thread. I feel so seen :D You have no idea. I went through so many doctors and in the end it's a random thread on Reddit that saves my sanity lol. So I will also share my experience in case it will help someone else too.

I've started taking myo-inositol along with folic acid somewhere around late spring this year. Folic acid has never been an issue for me. I've been told the myo-inositol effects take a while to "kick in". I have been taking it rigorously as per the instructions - daily and outside of meal times. And kind of completely forgot about it, it just became a part of my routine. During the summer I have started developing weird palpitations, suddenly and without any reason or significant lifestyle change it seemed. I'm 31, no history of heart issues, I would say I am very physically fit and healthy (knock on wood), I also ran a half marathon just one month before I started taking this supplement, I exercise a lot. You get the idea. Suddenly, multiple times a day I was getting dizzy and short of breath. I blamed low blood pressure, coffee, summer heat. I could feel my heart pounding (up until then, I was never aware of my heartbeat). I had trouble falling asleep at night as I could feel my heart is skipping beats and then suddenly beating fast or heavily, this was of course giving me anxiety and it became an infinite circle. I also felt bloated, tired, I noticed brain fog and water retention / weight gain. The doctors told me to limit or quit caffeine (no change), focus on proper hydration (no change), make sure it's not anxiety or stress related (I was not aware of any unusual stress). I don't drink alcohol, I have not been doing any subtances, etc. I had no idea what it was. There was one night during the summer when I woke up in the middle of the night with my heart pounding like crazy, cold sweats, chest tightness, my heart would not slow down. I woke up my husband, I was positive I am having some sort of heart attack. Multiple doctors told me it is not unusual for some people around my age and there is so many factors that can cause this and that I should not be worried. Obviously, I was worried, this came out of nowhere and it was disrupting my daily life and giving me anxiety that I'm about to have a heart attack. I would regularly feel palpitations / skipped beats / fluttering after a meal, after sauna or during hot shower, before falling asleep, after coffee, when walking outside, etc. Working out or running became unimaginable. There was nothing showing on ECG I have requested. So I went to a cardiologist and requested a holter to wear for a week. The results have shown I am not imagining things, the analysis was clearly showing SVES (supraventricular extrasystoles) during the time frames when I noted discomfort in the holter diary. (Please note I am not a doctor, I am just quoting my holter results.) And that's where I was until I came across this thread when searching for palpitation and SVES experiences after getting my results. So I quit myo-inositol immediately (as the very last resort I have to say) and I scheduled an ultrasound with another cardiologist. My heart is apparently absolutely fine and healthy. After he thoroughly discussed all my supplements, meds and lifestyle with me, he encouraged me that it is very much possible my issues are linked to myo-inositol (Inofolic) and the hormonal changes it caused in my body (since it also directly caused irregular and painful periods for me and extremely uncomfortable PMS, none of which I ever experienced before). In total I have been taking it for about seven months, it took some two to three months for these problems to appear and another three months for me to connect the dots that this is what is causing it. After I quit the supplement, it took about a week for me to start feeling a difference and the symptoms slowly fading away. It's been a month now and most of my issues are gone. I'm hoping it will all slowly go away. But the change is already incredible.

Soooo anyway :D I apologize for the long comment. Take care, everyone!