ZMA is a blend designed to aid in testosterone production and improve sleep quality, strength, and growth.

It’s made by Optimum Nutrition, a company that pride themselves on the use of “strict quality control, lab testing, and manufacturing under tightly controlled conditions… to bring you high quality, affordable supplements”.

Ingredients Label

Active Ingredients:

Zinc

Zinc is an essential mineral which is involved in many enzymes in the body.

It has been shown to increase testosterone levels in both those with Zinc deficiencies (1) and low testosterone levels (2), as well as prevent decreases in testosterone in healthy subjects after exercise (3).

Zinc methionine (4) and aspartate are widely accepted well-absorbed forms of Zinc. The daily recommended dosage is 15mg, and possibly more for athletes.

Magnesium

Magnesium is also an essential mineral, for which deficiency is very common.

It has a variety of positive effects including increasing aerobic performance (5) and increasing sleep quality (6). Higher quality sleep has been linked to higher testosterone levels (7).

The effective dose studied for improved sleep quality was equivalent to 51mg (8).

Vitamin B6

Vitamin B6, like Magnesium, has a range of benefits, and is important here due to its potential ability to increase absorption of Zinc (9).

The effective amount for this purpose is unknown, although Optimum Nutrition ZMA has the ‘typical’ amount seen in ZMA supplements.

Who Takes It?

ZMA is most effective in those who are deficient in Zinc, Magnesium, or Vitamin B6, or older males seeking testosterone support.

Benefits may be seen to a lesser extent in athletes or those wishing to improve quality of sleep.

How to Take

3 capsules, on an empty stomach before bed. Do not take with Calcium, as it can block Zinc absorption.

Side Effects

ZMA has been linked to vivid dreams, thought to be caused by vitamin B6 (10).

An increase in libido may be observed.

Conclusion

Optimum Nutrition’s ZMA is about building muscle growth by enhancing testosterone function.

It has a pretty strong forumla here, which could increase testosterone in those with below-normal levels, or those deficient in zinc.

The only problem is there are many other ingredients shown to boost testosterone which are not in ZMA.