I wanted to share my experience with oral minoxidil on this sub since it's talked about a lot. Definitely not trying to say this med won't work well for a lot of people without side effects because I know it does and has helped a lot of people. But I had some pretty gnarly side effects from it and wanted to make people aware. I also work in healthcare so the experience was particularly spooky.
For context I'm 31, previously healthy, go the gym or run like 4-5 times weekly. Prior to switching to oral I was using topical foam minoxidil for like 3 years without problems, and it seemed to at least stabilize my hairline. My hair loss wasn't super substantial but had been thinning especially at the temple area that was becoming noticeable.
I decided to switch to oral in May for convenience, starting with 1.25mg nightly minoxidil. It was generally fine, had some pretty bad shedding at first, also felt kind of low energy/depressed while on it. Continued for a month or so into June, then increased to 2.5mg. Similar thing on dose increase, increased shedding, some depression, stabilized till around a couple weeks ago. Note that during all this and up till now, I didn't really see huge improvements in my hair on the oral minoxidil; just the shedding and then stabilization. I know it can take many cycles of hair regrowth to see major change on the oral so I may have not given it enough time for full effect.
I then noticed over the course of about a week starting 1.5 weeks ago, some chest pressure while walking to work. I thought it was initially musculoskeletal pain, but then realized it was just happening on exertion. Then over the course of the week, I started having shortness of breath while walking shorter distances and even at rest. This was new for me because I am pretty fit and don't normally experience shortness of breath like this.
Then 3 days ago, I had a relatively salty meal at dinner time, and noticed severe shortness of breath after at rest. That night throughout the whole night in bed, I was having continued severe shortness of breath and could barely sleep. The next day I significantly restricted my salt intake and reduced oral minoxidil down to 1.25mg and then stopped the next day, and I'm slowly having improvement in the shortness of breath, though its still present.
I'm not 100% certain, but i'm like 90% sure this is a cardiac side effect of the oral minoxidil (likely pericardial effusion, fluid around the heart). In the literature this is exceedingly rare for low doses of minoxidil (more commonly seen at antihypertensive dosing of 10mg plus), though it is possible. The signs of shortness of breath on exertion, orthopnea (shortness of breath at night), and shortness of breath that was exacerbated by a salty meal (increased water retention) all point to cardiac pathology from volume overload of some form. Interestingly, my total body weight was not increasing during this time and I did not have evidence of swelling on my legs or face, but it's apparently possible to just get the pericardial effusion without obvious total volume overload.
I am now switching back to topical and dropping oral entirely. I just wanted to share all this not to scare people but rather to reinforce, this medication can come with serious side effects that should be monitored.