TRT and Hair Loss: What Every Man Should Know Before Starting Testosterone

There’s no denying it: testosterone replacement therapy (TRT) can be a game-changer. More energy, sharper focus, better workouts, a stronger libido—TRT has helped countless men feel like themselves again. But what about your hairline? Can getting your T levels back up also accelerate hair loss?

Let’s break down what’s really happening, why some men notice hair thinning after starting TRT, and how to protect your hair while optimizing your hormones.

The Science: How Testosterone Affects Hair

Testosterone itself isn’t the villain in this story—it’s actually the byproduct, dihydrotestosterone (DHT), that’s doing the damage. When testosterone is converted into DHT by the enzyme 5-alpha reductase, that more potent androgen binds to receptors in your hair follicles. In genetically susceptible men, this causes the follicles to miniaturize over time, leading to the hallmark signs of androgenetic alopecia—receding temples, thinning crown, and eventually, visible scalp.

TRT increases the total amount of testosterone in your system. For many men, that means more fuel for DHT production. This becomes particularly relevant for men with a genetic predisposition to androgenetic alopecia.

Studies suggest that as many as 50–70% of men will experience some degree of pattern hair loss by age 50, and introducing TRT can accelerate this process in those already genetically susceptible. In these cases, the follicles are sensitive to even modest increases in DHT, potentially speeding up miniaturization and visible thinning.

Does TRT Cause Hair Loss?

Not exactly. TRT doesn’t create a new hair loss condition out of thin air. But it can act like gasoline on a smoldering fire. If you were already destined to lose hair due to genetics, TRT may accelerate that timeline.

Here’s the key: TRT reveals your genetic cards—it doesn’t deal them. If your father or older brothers went bald, or if you’ve noticed early thinning already, your hair follicles are likely sensitive to DHT.

[Additional Reading: What Causes Hair Loss Besides Genetics? 10 Common Factors to Consider]

Can You Prevent Hair Loss While on TRT?

Yes—and your strategy should include both pharmaceutical and non-pharmaceutical approaches.

Pharmaceutical Defenders

For men on TRT, tackling DHT head-on often means incorporating medication. Pharmaceutical interventions target the root biochemical pathways behind hair loss, especially in those genetically predisposed. Here's how these therapies help preserve hair while optimizing hormone levels:

• Finasteride: A 5-alpha reductase inhibitor that lowers DHT levels by about 70%. Available in oral or topical formulations. Finasteride has shown significant efficacy in slowing or halting hair loss in men with androgenetic alopecia, including those undergoing hormonal therapy. While no large-scale clinical trials have studied finasteride specifically in men on TRT, its mechanism—reducing scalp DHT—remains effective regardless of testosterone status.

• Dutasteride: Even more potent than finasteride, it inhibits both type I and type II 5-alpha reductase enzymes and can reduce DHT levels by up to 90–98%. It’s often used when finasteride isn’t strong enough or when faster, more pronounced results are desired. Emerging clinical data suggests dutasteride offers enhanced hair regrowth benefits in DHT-sensitive men, though formal studies pairing it directly with TRT are limited.

• Minoxidil: A vasodilator that boosts blood flow and helps follicles stay in the growth (anagen) phase. Works well in combination with DHT blockers and is often recommended as part of a synergistic treatment plan.

Flycatcher offers genomic testing, which analyzes an individual’s genetic sensitivity to DHT. The results inform the formulation of a personalized prescription topical, typically combining minoxidil with topical DHT blockers and other active ingredients. This customized approach ensures that patients receive a targeted therapy designed to directly counteract the DHT-related effects driving their specific pattern of hair loss.

[Additional Reading: Finasteride Side Effects & Libido - What to Know]

The Flycatcher + GetHairMD Advantage

Flycatcher clients also have access to GetHairMD™, a comprehensive, non-invasive hair restoration system designed to reduce DHT’s impact and preserve hair health from multiple angles:

• Clinical Hair Growth Laser: This FDA-cleared in-office device uses low-level laser therapy (LLLT) to increase blood flow, reduce inflammation, and improve follicular activity. Enhanced circulation helps mitigate DHT’s constrictive effects on follicle nutrition and oxygenation.

• Dual Wave Energy Cap: A take-home LED device that emits both red and orange light wavelengths to boost mitochondrial activity and reduce local DHT expression, promoting a healthier follicular environment.

• Follicular Infusion System: Delivers growth factors and nourishing compounds directly to the follicle base. This infusion not only supports growth but also reinforces follicle resilience against DHT-induced miniaturization.

• Medical-Grade Replenish Shampoo with DHT Blockers: Formulated specifically to cleanse the scalp while delivering mild, topical DHT inhibitors and anti-inflammatory agents. It supports daily maintenance by keeping the scalp in optimal condition and reducing androgenic impact over time.

Together, these in-clinic and at-home therapies form a synergistic defense system that targets DHT at multiple levels—systemic, local, topical, and environmental.

Before You Start TRT: Know Your Hair Risk

Before jumping into TRT, it’s smart to assess your hair loss risk. Hormonal optimization has many benefits, but for men with a predisposition to androgenetic alopecia, it can also act as a catalyst for accelerated thinning. Being proactive allows you to make informed decisions and preserve your hair as you enhance your vitality.

• Family History: Is hair loss common in your bloodline? If your father, grandfather, or uncles showed signs of balding, your risk is significantly higher.

• Early Signs: Noticeable changes in your hairline or crown, increased shedding in the shower, or widening part lines can all be early warning signs.

• Hair Density Scan: Tools like our HairMetrix device can create a digital baseline to track changes over time, giving providers a non-invasive way to measure follicular health and determine whether a preventative approach is necessary before TRT begins.

Flycatcher's recommendation: Visit us for a comprehensive Scalp & Hair Health Consultation. We'll analyze your follicular health with our HairMetrix device and put together a personalized treatment plan for you. We can do your genomic testing during the same visit. 

If you're at high risk, consider starting a hair loss prevention plan before or alongside your TRT. The earlier you intervene, the better your chances of keeping your hair.

Final Thoughts

TRT and a strong hairline don’t have to be mutually exclusive. Understanding the connection between testosterone, DHT, and your follicles is the first step. From there, it’s all about proactive strategy—using the right tools, therapies, and technology to protect what’s yours.

Flycatcher is proud to offer the full GetHairMD suite to help men navigate this journey with confidence. Whether you’re just starting TRT or already on it, you don’t have to choose between feeling great and looking sharp.

At Flycatcher, we’ll help you make the most informed decision for your hair and your long-term confidence.

Conveniently located just west of the Galleria in Bee Cave, we proudly serve Spicewood, Lakeway, Bee Cave, and the greater Austin area. Call or text (737) 239-0112 today to schedule a no-obligation consultation, including hair analysis and genomic testing.

Early action means better results—don’t wait until it’s too late.