Testosterone, DHT, and Gains: What Actually Builds Muscle

There's a persistent myth in fitness communities: DHT is "the powerful androgen," so blocking it must hurt muscle growth. This misunderstanding causes guys to avoid hair loss treatment, fearing they'll sacrifice gains.

The reality is more nuanced—and more reassuring. Let's dive into what the science actually shows about androgens and muscle.

The Two Androgens: A Comparison

The "3x More Potent" Misunderstanding

You'll often hear that DHT is "3-5x more potent than testosterone." This is technically true—but misleading in the context of muscle.

Potency refers to binding affinity to androgen receptors. DHT binds more strongly. But here's what matters: potency only matters where the hormone is present.

Muscle tissue has very little of the enzyme (5-alpha reductase) that converts testosterone to DHT. So while DHT is theoretically more potent, it's barely present in muscle. Your muscles run on testosterone—the hormone finasteride leaves intact (and even slightly increases).

Where DHT Actually Acts

DHT's effects are concentrated in specific tissues:

• Scalp: Causes follicle miniaturization (hair loss)
• Prostate: Drives growth (benign enlargement)
• Skin: Affects sebum production and body hair
• Brain/Mood: Possible neurological effects

Notice what's missing? Muscle. The tissues where DHT is active are not the tissues responsible for hypertrophy.

The Testosterone Preservation Effect

Here's the counterintuitive part: by blocking DHT conversion, finasteride actually increases circulating testosterone.

Under normal conditions, approximately 5-10% of testosterone converts to DHT. When you block this conversion:

• Less testosterone is "lost" to DHT conversion
• More free testosterone remains available
• Studies show approximately 15% increase in serum testosterone

Your muscles see slightly MORE of their preferred androgen, not less.

What the Research Shows

Studies examining finasteride users versus non-users consistently find:

• No difference in lean body mass
• No difference in strength measurements
• No difference in exercise performance
• No difference in body fat percentage

If DHT were critical for muscle building, we'd expect finasteride users (with 70% lower DHT) to show measurably worse outcomes. They don't.

What About During Puberty?

One valid question: if DHT doesn't build muscle, why does it matter during puberty?

During development, DHT plays specific roles in sexual differentiation and certain secondary sex characteristics. But post-puberty, its role shifts primarily to:

• Maintaining prostate tissue
• Affecting hair follicles (positively for body hair, negatively for scalp)
• Influencing sebaceous glands

Adult muscle hypertrophy doesn't depend on DHT. That's testosterone's domain.

The Steroid World Confirms This

If you look at what performance-enhancing drug users actually take for muscle growth, it's testosterone and testosterone derivatives—not DHT-based compounds. The few DHT derivatives that exist (like Masteron) are used for "hardening" and cosmetic effects, not for building mass.

The bodybuilding world, despite all its experimentation, has confirmed through decades of practice that testosterone is the muscle-building androgen.

Practical Implications

For men who want to optimize both hair and fitness:

1. Finasteride won't hurt your gains. The science is clear on this.
2. Focus on training fundamentals. Sleep, nutrition, and progressive overload matter infinitely more than androgen ratios within the normal range.
3. Don't sacrifice one goal for a false fear. You can maintain your hair without compromising gym performance.

The Bottom Line

Testosterone builds muscle. DHT miniaturizes hair follicles. These are different jobs in different tissues. Blocking DHT for hair preservation doesn't impair muscle growth because muscle tissue wasn't using DHT for growth in the first place.

The fear of losing gains from finasteride is based on a misunderstanding of androgen biology. You can keep your hair and keep building muscle.

References

• Research on 5-alpha reductase tissue distribution.
• Studies on androgen receptor binding and tissue specificity.
• Finasteride and body composition research.
• Testosterone's role in muscle protein synthesis.