First, I am not a supplement guy.
The supplement industry is in business to do what? Sell supplements right, so as a guy who grew up in the 70’2, 80’s and beyond, almost all of the supplements then were USELESS and I bough all of them.
After spending thousands of dollars on NOTHING except a full toilet bowl I only suggest products that have been proven for years to do what they claim.
and the most important of all
With that said, I would evaluate your nutrition plan and make it consist of whole foods that re inline with your goals.
Once that is done, add in one of the supplements I listed one at at time and see if they work for you as advertised.
After that, it’s up to you.
When adding supplements to your diet remember 2 things:
1. They are SUPPLEMENTS to an already dialed in nutrition plan. Pills and potions do not fix a bad diet.
2. Add them one at a time and see if they have they desired affect.
If you add a bunch at once you never know which one worked-or didn’t.
I will reserve my opinion on the ones you listed, but I am guessing you can tell what I think.
Let me know how it goes.
As to how they make claims, it is easy to fund a study. Remember, a study is meant to prove or disprove something and it can easily be set up to get the desired results.
Also, the industry is very unregulated so they can make virtually any claim they want.