Steroid prohormones such as androstenedione and dehydroepiandrosterone (DHEA) have become popular in recent years as safer alternatives to anabolic steroids, but two questions need to be answered:

1. Are they effective in stimulating muscle growth?

2. Are they safe to use?

The theory behind prohormones is that they are building blocks for testosterone and are converted into testosterone by the body. Very little definitive scientific research exists to back up the claims of prohormone manufacturers. The difficulty seems to be that the minimum dosage levels recommended by manufacturers appear to be insufficient to stimulate a measurable clinical reaction. Many users point to the effectiveness of prohormones when doses that exceed recommended levels are taken, hence the difficulty for researchers - do you subject human participants to potentially dangerous doses?

Safety concerns are similar to those that relate to steroids. Some studies report that side effects can include acne, production of estrogen, development of breast tissue in males and development of masculine features in females.

At the time of writing some doubts surround the future of prohormones as health authorities may consider selective banning of some products.