The question seems to be worded with the slant that all supplements are a waste?
Alcohol has a measurable effect on the body, and no one questions it.
Nicotine has a measurable effect on the body, and no one questions it.
Caffeine has a measurable effect on the body, and no one questions it.
But suddenly when something is labeled a supplement, it’s snake oil.
I take a vitamin in the morning, I have no conclusive proof it does anything but the only reasons I’ve read not to take one involve risks with extreme doses of certain items. I don’t trust my diet to get me everything I need so $6/mo is cheap insurance and anecdotally I seem to get sick less when I take it. I talked it over with my doctor and a nutritionist. The nutritionist highly recommended it, the doctor’s conclusion was “it can’t hurt”.
Most of the other stuff I’ve tried falls into either trying to help me sleep, or trying to help me heal up.
To sleep I’ve tried magnesium based stuff like Natural Calm, and I’ve tried melatonin pills.
The Natural Calm is definitely relaxing and I prefer it to sleeping pills. I don’t use it very often because it makes me feel dopey until I fall asleep, makes me burp, and I wake up with a strange taste in my mouth. I still use it if I need to sleep, but it’s not perfect.
The melatonin pills didn’t work for me. I’m not consistently ready to sleep at a certain time so it may work for others as the whole point seems to be establishing a rhythm.
As far as healing I’m a skinny guy who likes to play sports and I get worn down. I’ve had trouble and injuries with my legs and tried a common mix of Glucosamine, Chondroitin and MSM that seemed to really help with my knees and ankles. I’ve read studies that go both ways on these, but the difference was pretty dramatic for me in terms of pain.
When I had a physical job, I used a creatine supplement and it helped me feel less beat down after a long week.
I guess I also use a drink mix and meal replacement bars as a way to eat decent when good food isn’t always available or you don’t have time to cook something healthy up. I’d recommend them to anyone. I’m not sure if they fall under this definition of supplements or not, I just consider them food.