Intermittent Fasting While on Prohormones: A Good Idea?

Bodybuilders are no strangers to pushing the limits of nutrition and supplementation. Two popular strategies — intermittent fasting (IF) and prohormone cycles — are often used to sculpt muscle, shred fat, and maximize anabolic potential. But what happens when you combine them? Can intermittent fasting interfere with your prohormone cycle, or do they actually complement each other? Let’s break it down.

How Prohormones Work in the Body

Prohormones are precursors to anabolic hormones. Once ingested, your body metabolizes them (usually in the liver) into active compounds with anabolic properties — helping increase strength, muscle density, and recovery.

Because they stress the liver and endocrine system, timing, diet, and recovery are just as important as the compound itself. Without the right environment, even the strongest prohormone won’t deliver its full potential.

The Intermittent Fasting Factor

Intermittent fasting (IF) — typically structured as 16:8 (16 hours fasting, 8-hour eating window) — has become popular among athletes for fat loss and insulin sensitivity benefits. But IF creates unique metabolic conditions that can clash with prohormone use if you’re not careful.

5 Potential Issues When Combining IF and Prohormones

1. Absorption Problems

Most prohormones are fat-soluble, meaning they’re absorbed far better when taken with food — especially with dietary fat. If you’re dosing them in a fasted state, you’re leaving gains on the table and possibly irritating your stomach.

2. Hormonal Tug-of-War

Prohormones push the body into an anabolic state. Extended fasting elevates cortisol (a catabolic hormone). That’s two opposing forces fighting inside your body. Translation: less growth, more stress.

3. Catabolism vs. Anabolism

Fasting for long stretches without protein can push the body into muscle breakdown. Prohormones can only do so much if the raw materials — amino acids — aren’t available. Think of it like trying to build a house without bricks.

4. Liver Load

Both IF and prohormones shift liver function. Fasting alters glycogen levels, while prohormones are often hepatotoxic. Running both together without proper support can magnify liver strain.

5. Training Fuel

Fasted workouts may be fine for casual lifters, but when you’re on cycle, you want to train heavy, recover hard, and grow. Without pre-workout carbs and amino acids, you’ll undercut the performance benefits that prohormones provide.

Best Practices If You’re Running Both

If you’re determined to mix intermittent fasting with a prohormone cycle, here’s how to do it smarter:

• Always take with food: Dose prohormones during your eating window with fats (e.g., eggs, nut butter, avocado).

• Break the fast before training: Don’t train heavy while fasted on cycle — fuel up first.

• Hit protein targets: Make sure your eating window still delivers 1–1.2g protein per lb of bodyweight.

• Protect your liver: Use liver-support supplements like NAC, milk thistle, or TUDCA.

• Stick to 16:8: Longer fasts (24–48 hrs) are counterproductive and risky during a cycle.

• Hydrate: Fasting + prohormones = extra strain. Keep fluids and electrolytes high.

The Bottom Line for Bodybuilders

Intermittent fasting isn’t inherently unsafe with prohormones, but it can reduce absorption, increase hormonal stress, and blunt muscle-building results if done carelessly.

If your primary goal is maximum growth, a traditional bodybuilding meal plan will likely outperform intermittent fasting during a prohormone cycle. But if you prefer IF for lifestyle or fat loss reasons, you can make it work with a disciplined approach: dose with meals, break fasts before workouts, and never compromise protein intake.

At the end of the day, prohormones are about creating the most anabolic environment possible. Make sure your nutrition strategy supports that goal — not fights against it.

Author

Jeff has been in the fitness and supplement industry for almost 20 years. He is an avid bodybuilder and helps others with lifting techniques, as well as the best vitamins and supplements they should take for the goals they have. You can find him on LinkedIn and Youtube.

Jeff Moriarty