METHYLSTENBOLONE (M-STEN)

METHYLSTENBOLONE IS NO LONGER AVAILABLE, TRY THESE ALTERNATIVES...

Methylstenbolone has been ruled by the FDA to no longer be a legal dietary ingredient, and thus supplements like Assault Labs MSten Extreme Mass Builder are no longer able to be sold. Here are some similar and effective alternatives to help you build lean muscle mass, and to acquire increased strength and gains.

If you're looking for more information you can checkout our ProHormone Guide, or the list of our Top 10 ProHormones for 2025.  

Methylstenbolone or MSten is a mass-building prohormone that helps users gain size and strength without sacrificing definition. M Sten is derived from DHT, so it doesn’t convert to estrogen, resulting in little to no water retention.

Methylstenbolone is methylated, so liver toxicity is associated with this compound. Taking a Cycle Support product can help minimize or eliminate the potential for side effects while on cycle.

Following a healthy diet, training intensely, and proper use of MSten can result in gains of 5-20 lbs of lean muscle mass during a cycle.

• Size Gains
• Mass Gains
• Strength Gains
• Zero Conversion to Estrogen
• Muscle Density Increase

• Liver Toxicity
• Increased Blood Pressure
• Back Acne
• Headaches
• Mood Swings
• Lethargy
• Aggression

A typical cycle of Methylstenbolone should last 4 weeks for normal users. Advanced users may extend their cycles, but should start with lower doses.

Beginner & Intermediate Users

Week 1: 4-8mg per day with proper liver care and cycle support

Week 2-3: 8mg per day with proper liver care and cycle support

Advanced Users:

 Week 1: 8mg per day with proper liver care and cycle support

Week 2-3: 12mg per day with proper liver care and cycle support

Week 4: 16mg per day with proper liver care and cycle support

Yes. A cycle support is always recommended during prohormone cycles, especially with methylated products.

Cycle Support helps minimize side effects. If you experience issues with back acne, try using Taurine.

• Regulates Hormone Levels
• Supports Prostate Health
• Lowers Blood Pressure
• Protects Liver and Kidney
• Improves Immune Function
• Enhances Mood

Always. Post Cycle Therapy helps restore natural testosterone levels. It helps to lock in those hard-fought gains you made.

• Restores Natural Testosterone Levels
• Detoxifies Your Body
• Increases Libido
• Improves Immune Function
• Helps Prevent Side Effects