Howdy Murdock325:
Metabolife has a bunch of stuff in it, some of which might not mix well with diving. I haven't brought up my board mantra in awhile, so now's a good time.
All-natural doesn't equal safe. If you take it to have an effect, it can also have
sideeffects.
Hemlock is all-natural. Deadly Nightshade is all-natural. Arsenic is all-natural.
Let's look at a few of the herbal ingredients in Metabolife and their effects. (Note, I can't vouch for the accuracy of the following list of ingredients, or the accuracy of the rain-tree.com or health-doc.com sites I'm referring you to, but it's the best I could find on the web and I'm offering it for example purposes.)
Guarana (
http://www.rain-tree.com/guarana.htm)
Ma Huang (
http://www.health-doc.com/healtharticles/MaHuang.html)
Damiana (
http://www.rain-tree.com/damiana.htm)
Sarsaparilla (
http://www.rain-tree.com/sarsaparilla.htm)
Nettles (
http://www.rain-tree.com/nettles.htm)
You can see that there are stimulants and diuretics on the list. The Ma Huang is a particularly worrisome ingredient and I would guess the main active ingredient in Metabolife. It contains ephedrine which is a chemical in the sympathomimetic amine family (like adrenaline). Remember, drugs have that have effects can have side effects.
Pseudoephedrine in frequently used by divers for it's ear and sinus clearing effects, but it can also have
side effects. (Do a board search on pseudoephedrine.) Ephedrine would have similar effects and side effects, but in most people ephedrine is more likely to cause the unacceptable side effects. There is a move to ban ephedrine containing herbal medicines in my State after some users have died from the side effects. If Metabolife has a significant diuretic effect, that would not be too great for a diver either.
HTH,
Bill