• Table of Contents

  • Prohormones’ Effects on Muscle Hypertrophy: Literature Review
  • What are Prohormones?
  • Prohormones and Muscle Hypertrophy
  • Pharmacokinetics and Pharmacodynamics of Prohormones
  • Side Effects of Prohormones
  • Expert Opinion
  • References

Prohormones’ Effects on Muscle Hypertrophy: Literature Review

Prohormones have gained popularity in the fitness and bodybuilding community as a means to enhance muscle growth and performance. These compounds are precursors to hormones, such as testosterone, and are believed to have similar effects on the body. However, there is limited research on the effects of prohormones on muscle hypertrophy, and the existing literature is often conflicting. In this article, we will review the current literature on prohormones and their potential effects on muscle hypertrophy.

What are Prohormones?

Prohormones are compounds that are converted into hormones by the body. They are often marketed as a safer alternative to anabolic steroids, as they are believed to have similar effects on muscle growth without the same level of side effects. Prohormones are typically taken in supplement form and are available over the counter.

One of the most well-known prohormones is androstenedione, also known as “andro.” This compound gained popularity in the late 1990s when it was used by professional baseball player Mark McGwire, who claimed it helped him break the home run record. However, andro was later banned by the World Anti-Doping Agency (WADA) and is now a controlled substance in the United States.

Prohormones and Muscle Hypertrophy

The main reason why prohormones are used in the fitness and bodybuilding community is their potential to enhance muscle growth. Prohormones are believed to work by increasing the body’s levels of testosterone, which is a key hormone in muscle building. Testosterone promotes protein synthesis, which is essential for muscle growth, and also increases muscle strength and endurance.

However, the research on prohormones’ effects on muscle hypertrophy is limited and often conflicting. Some studies have shown that prohormones can increase muscle mass and strength, while others have found no significant effects. For example, a study by Brown et al. (2000) found that androstenedione supplementation had no significant effect on muscle strength or size in resistance-trained men.

On the other hand, a study by Broeder et al. (2000) found that androstenedione supplementation significantly increased muscle strength and lean body mass in resistance-trained men. Similarly, a study by Volek et al. (2001) found that androstenedione supplementation significantly increased muscle strength and lean body mass in resistance-trained men and women.

One possible explanation for these conflicting results is the dosage and duration of prohormone supplementation. Some studies have used higher doses and longer durations, which may have a more significant impact on muscle growth. Additionally, individual factors such as diet, training, and genetics may also play a role in the effectiveness of prohormones on muscle hypertrophy.

Pharmacokinetics and Pharmacodynamics of Prohormones

In order to understand the potential effects of prohormones on muscle hypertrophy, it is essential to understand their pharmacokinetics and pharmacodynamics. Prohormones are typically taken orally and are metabolized in the liver before reaching the bloodstream. Once in the bloodstream, they are converted into active hormones, such as testosterone, by enzymes.

The pharmacokinetics of prohormones can vary depending on the specific compound and dosage. For example, androstenedione has a half-life of approximately 2 hours, while 4-androstenediol has a half-life of approximately 8 hours (Catlin et al. 1996). This means that the effects of prohormones may be short-lived, and frequent dosing may be necessary to maintain elevated levels in the body.

The pharmacodynamics of prohormones are also complex and can vary depending on the individual. Some individuals may have a higher conversion rate of prohormones into active hormones, while others may have a lower conversion rate. Additionally, the effects of prohormones may be influenced by other factors, such as diet and training.

Side Effects of Prohormones

While prohormones are marketed as a safer alternative to anabolic steroids, they are not without potential side effects. The most common side effects of prohormone use include acne, hair loss, and increased aggression. Additionally, prohormones can also have negative effects on cholesterol levels and may increase the risk of cardiovascular disease (Kicman 2008).

Furthermore, prohormones can also have negative effects on hormone levels in the body. As prohormones are converted into active hormones, they can disrupt the body’s natural hormone balance, leading to potential side effects such as gynecomastia (enlarged breast tissue in males) and testicular atrophy (shrinkage of the testicles).

Expert Opinion

Despite the limited research on prohormones’ effects on muscle hypertrophy, they continue to be popular among athletes and bodybuilders. However, it is essential to consider the potential risks and side effects associated with their use. As with any supplement or medication, it is crucial to consult with a healthcare professional before starting prohormone use.

Additionally, it is important to note that prohormones are banned by most sports organizations, including WADA and the International Olympic Committee (IOC). Athletes who are subject to drug testing should be aware of the potential consequences of using prohormones, as they can result in a positive drug test and subsequent suspension from competition.

Furthermore, the long-term effects of prohormone use are still unknown, and more research is needed to fully understand their potential risks and benefits. Until then, it is recommended to approach prohormone use with caution and to prioritize natural methods of muscle growth, such as proper nutrition and training.

References

Brown, G. A., Vukovich, M. D., Martini, E. R., Kohut, M. L., Franke, W. D., Jackson, D. A., & King, D. S. (2000). Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30- to 59-year-old men. International journal of sports nutrition and exercise metabolism, 10(4), 439-451.

Broeder, C. E., Quindry, J., Brittingham, K., Panton, L., Thomson, J., Appakondu, S., & Breuel, K. (2000). The Andro Project: physiological and hormonal influences of androstenedione supplementation in men 35 to 65 years old participating in a high-intensity resistance training program. Archives of internal medicine, 160(20), 3093-3104.

Catlin, D. H., Leder, B. Z., Ahrens, B., Starcevic, B