I’ve struggled with restless leg syndrome most of my adult life. I started taking magnesium supplements and my symptoms have all but disappeared. I don’t care if it’s a placebo effect or not, my legs don’t twitch anymore.
I was having a lot of trouble with my nails breaking and splitting, especially considering the art work I do. Then I started taking 10,000 mcg of Biotin every day. I could see that my nails were getting thicker, but it took 9 months for the thicker nails to grow out to the tips. I still had a little breaking, so I upped the dosage to 15,000 mcg. They’re still growing out.
I took triple-strength glucosamine/chondroitin for several years. It did absolutely no good whatsoever. I wound up having knee replacement surgery… which is NOT a panacea.
5-HTP for sleep. Melatonin makes my throat feel like it is swelling and choking me. I take 5HTP 30 minutes before sleep while traveling and it works like a charm.
Now it is recommended for general mood smoothing, but I only use it for red-eye flights and time shifting.
When I was a kid I would get cold sores a couple times each winter (usually following a cold), and the visible scabs on my lip or nose would render me a social outcast. A Dr. suggested I take L-Lysine regularly to ward them off, and I believe there was a reduction in the frequency and if one did emerge, it was smaller and shorter-lived than without the supplement.
Like the OP, I cannot conclusively credit L-Lysine with preventing my cold sores (it could have just had to do with me getting older, less illnesses, etc), but at the time I felt like I was “doing” something about it rather than waiting to be a victim.
I don’t know if I had any symptoms of anemia but my hemoglobin was quite low when I went to donate blood (like 9 or 10? It should be 12.5 or higher), two times in a row.
I take an iron supplement now and it’s consistently good. Except for that one time I stopped taking it out of laziness (ran out, didn’t buy more) and it was too low to donate again.