Is testosterone therapy the holy grail for midlife energy and libido or just another biohacking fad?

Last week, the New York Times finally covered testosterone therapy for women. I was glad to see it.

A decade ago, when I was first training in functional medicine at a high-end anti-aging clinic, testosterone was prescribed to men all the time. But for women? Almost never. Even in “forward-thinking” clinics, testosterone for women was rare. That gender bias stuck with me.

Now, the pendulum is swinging in the other direction. Women are finally getting access to testosterone, which is a major step forward. The problem is it's often prescribed at doses that are way too high. The result: acne, hair loss, mood swings, and even clitoral enlargement.

The truth is, most women—but not all—do benefit from testosterone support as part of a thoughtful HRT plan. The benefits to mood, energy, libido, bone, and muscle health are well-documented.

Let’s dig into what testosterone actually does (for women and men), when HRT makes sense, and how to find your optimal dose.

🤓 What to know: Testosterone is an essential longevity hormone for both women and men.

Testosterone is an androgen—a sex hormone produced in women by the ovaries and adrenal glands, and in men by the testes.

Two key forms matter:

• Total testosterone = the overall amount circulating in your blood.

• Free testosterone = the biologically active portion (1–3%) that’s not bound to proteins like SHBG and can bind to receptors in your brain, muscles, and tissues.

In both women and men, testosterone supports:

• Libido and sexual satisfaction

• Muscle mass and strength

• Bone density and remodeling

• Mood, motivation, and energy

🔽 Testosterone declines with age

♀️For Women:

• Begins dropping in the mid-30s

• By menopause, levels can fall by up to 50%

❌ Add chronic stress? That depletes DHEA, a key precursor to testosterone.

❌ Add oral birth control, low-protein diets, or thyroid imbalance? Those can raise SHBG, trapping more testosterone and lowering the free, usable form.

♂️For Men:

• Peaks in late teens to early 20s

• Declines by ~1% per year after age 30

❌  Stress, poor sleep, excess body fat, and inactivity accelerate that decline and promote conversion of testosterone to estrogen.

🚺 Testosterone Is Still Missing from Most HRT Plans

Most women are prescribed standard HRT—typically an estrogen patch and oral progesterone—and that’s it.

No hormone testing. No personalization. And rarely any discussion of testosterone.

Why?

• Testosterone is regulated and requires an in-person prescription in some states, which limits access.

• Most OB-GYNs and PCPs weren’t trained in modern hormone science or how to prescribe HRT in a balanced, responsible way.

• Many doctors still believe HRT is dangerous, despite strong evidence that HRT reduces risk for breast cancer, dementia, osteoporosis, and heart disease.

• Online hormone clinics have exploded, but most are built for men. The few that focus on women often skip testing and personalization entirely.

📉 The result? A generation of women being told they’re “treated,” while a crucial hormone is completely overlooked.

⚖️ Side Effects usually mean you’re overdosed

Symptoms in women and men can be obvious:

In Men:

• Acne

• Hair loss

• Mood swings or aggression

• Increased red blood cell count (which can raise clot risk)

• Testicular shrinkage

• Infertility

In Women:

• Acne and oily skin

• Hair loss (a supplement like saw palmetto can help)

• Rage or increased irritability

• Fluid retention

• Clitoral enlargement (especially when using high-dose cream directly on genitals)

🚫 Who Should Avoid Testosterone Therapy

Testosterone isn’t for everyone. Situations where it should be avoided include:

• History of breast or prostate cancer (especially hormone-sensitive) → A portion of testosterone is converted to estrogen in the body, which may stimulate tumor growth or recurrence.

• Severe cardiovascular disease or elevated red blood cell count → Testosterone can thicken the blood, raising the risk for stroke or heart attack.

• Pregnancy or breastfeeding → T can disrupt fetal development and may lower milk supply by suppressing prolactin.

• Untreated PCOS, severe acne, or androgenic alopecia → Testosterone may overstimulate already sensitive androgen receptors and oil glands.

• Lack of hormone testing → If you haven’t had a full hormone panel, don’t guess—test first.

💪 What to do: Start testing in your 30’s and dose for balance, not biohacking.

Here’s how I think about testosterone therapy for myself and my patients: 

I'm 44 and currently test my sex hormones twice a year through Parsley Longevity Labs. Right now, my testosterone is in the low-normal range. I feel great: no symptoms of perimenopause, no issues with mood or libido. So I’m not taking any HRT yet.

When my total T drops below ~20 ng/dL and I start feeling symptoms—fatigue, low libido, difficulty building muscle—that’s when I’ll add support.

🧪 Step 1: Test—Don’t Guess

Get baseline levels of:

✔️ Total and free testosterone

✔️ Estrogen

✔️ Progesterone

✔️ DHEA

Too many clinics skip this. That’s how women end up on male-level doses—and with avoidable side effects.

⚖️ Step 2: Dose for Balance, Not Biohacking

Most women feel best when their levels match those seen in their 20s–30s:

• Total T: 40–70 ng/dL

• Free T: 1.1–4.5 pg/mL

You don’t need sky-high numbers to see big benefits, just the right amount, consistently delivered.

💊 Step 3: Pick the Right Delivery Method

💧 Topical creams or gels: My go-to for women.

• Absorbed through the skin, easy to titrate and adjust. 

• Absorption varies person-to-person, so test regularly.

💎 Pellets: Convenient but inflexible. 

• Tiny implants under the skin that release testosterone over 3–4 months.

• If you’re over- or under-dosed, you’re stuck until it wears off. (We don’t use at Parsley.)

💉 Injections: Not ideal for women due to hormonal peaks and crashes.

Whatever you choose: monitor levels, track symptoms, and adjust over time.

⚡️ Quick Hits

🦴Microplastics harm bone health 

A recent review found that bone-building cells absorb micro- and nanoplastics, triggering inflammation, breaking down bones and inhibiting bone building function. 

Yet another reason I’m taking AlgeCal Plus to promote osteoblast activity and build bone mineral density. 

🧠 Creatine isn’t just for workouts

A new 12-week RCT showed it improved memory, attention, and executive function. It may even help delay or slow early cognitive decline. 

Add 3-5g of clean creatine to your morning H2O.   

💇‍♀️ Your = early hormone signal

A new study shows menopausal hormone changes can affect hair follicles a decade before you start noticing other symptoms.

If you're experiencing hair loss or changes get Parsley Longevity Labs ASAP as a starting point. 

💛 The Momgevity Files

TIf you follow me on Instagram, you know I just got back from Las Vegas, where I spoke on a panel at HLTH—which I call the “Super Bowl” of healthcare conferences.

I’ve been going for years, and let’s just say: wandering through smoke-filled casinos and not seeing daylight for 48 hours is not my idea of a healthy time. The irony of 10,000 healthcare execs defining the future of the industry in that setting always makes me laugh.

This year, though, I finally decided to Vegas my way. I landed and went straight to Whole Foods to stock up on snap peas, hummus, shrimp cocktail, glass-bottled water, and macadamia nuts so I could avoid eating out when I didn’t need to. I also hit the gym for a 20-minute weight session and stretch as soon as I checked in to boost my metabolism and get blood flowing after flying. And before diving into back-to-back meetings, I went outside to work for an hour by the pool in actual sunlight, to reset my circadian rhythm.

I’ve skipped those things in previous years, and wow—it made a difference. My energy was steadier, my sleep was better, and I actually felt good the whole time.

It was a good reminder that sometimes we have to work a little harder if we want something better than the status quo—especially when it comes to health.

That point hit home again for me on stage. One of my fellow panelists—a brilliant cofounder of a women’s health startup—said she believes the only things we access for our health should be covered by insurance.

In a rare moment of abject disagreement, I had to jump in.

I understood what she meant. We all spend a lot on insurance through our paychecks and taxes, and I deeply wish the right care was always covered. But the simple fact is—it’s not.

Insurance covers very basic screening, and catastrophe if you become very ill. But sadly, it covers very little in between. 

For example, insurance doesn’t pay for hormone testing for women, or DEXA scans to assess bone density before you're 65—even though bone loss starts in your 30s. It doesn’t cover mercury testing, even though our sushi habit has pushed U.S. mercury levels through the roof, harming brain health and immunity.

It doesn’t fund prevention or health optimization. It pays for disease management.

Even many of the female-founded companies doing great work in women’s health are still bound by those same limitations—because when insurance dictates the limits of care, quality suffers. (At Parsley, we’re in-network for about 16 million people, but we also charge a program fee for non-covered services—because our model goes far beyond what insurance pays for.)

The reality is: if we only accept what’s covered today, despite how outdated and out of sync the insurance system is with our needs, we’ll never be well.

So just like I draw my own line around Vegas—a place that’s comically expensive yet fails to give me what I need (groceries, gym, sunlight, sleep)—I draw one for our medical system, too.

The flow of the system is what’s making us sick. I’d rather step out of it and be a wellness warrior. The alternative is being the worried sick—and sadly, insurance doesn’t pay for that either.

Stay strong, stay curious, and breathe—
Robin

As always, this newsletter is for informational and educational purposes only and is not intended as medical advice. Always consult your healthcare provider before making any health decisions or changes to your treatment plan.