By Dr. John A. Robinson, NMD & Dr. Cristina Romero-Bosch, NMD
The Hormone Zone
For nearly 20 years, we have used a therapeutic total testosterone range of approximately 70–150 ng/dL in appropriately selected women. This has never been about simply pushing a laboratory number higher. Our approach developed from years of treating women, following symptoms and clinical response, monitoring laboratory values, and observing changes in sexual desire and function, energy, strength, body composition, mood, and overall quality of life. As the scientific literature surrounding testosterone in women continues to evolve, an important distinction is becoming increasingly relevant: the difference between a physiologic reference range and a therapeutic range.
This conversation is particularly exciting because testosterone therapy for women is finally receiving greater attention. Over the past several years, we have watched a significant shift in the way physicians, researchers, and women themselves talk about hormone therapy. After decades in which women’s hormone health was often reduced primarily to estrogen—or hormone therapy itself was approached with considerable fear—the discussion is becoming broader and more sophisticated. Testosterone, sexual health, muscle, bone, metabolic health, and quality of life are increasingly becoming part of the larger conversation about women’s health and healthy aging.
In many ways, we believe we are entering a golden age of women’s hormone therapy. That does not mean abandoning caution or pretending every question has been answered. It means better research is allowing us to ask better questions. The resurgence of interest in menopausal hormone therapy, combined with increasing scientific attention to testosterone in women, is moving the field beyond the simplistic question of whether women should receive hormones at all. The more meaningful questions are becoming: Which hormones are appropriate for which woman, at what dose, at what stage of life, and toward what therapeutic goal? For those of us who have been practicing comprehensive hormone therapy for decades, it is encouraging to see the scientific conversation finally expanding in this direction.
What Is a “Normal” Testosterone Level in Women?
Wainwright and colleagues recently published Redefining Testosterone Reference Ranges for Adult Females in the Journal of Endocrinological Investigation. Researchers evaluated testosterone measurements from 5,323 carefully selected women between ages 19 and 59 with normal BMI, regular menstrual cycles, and no known reproductive disorders.
Their findings challenge the usefulness of thinking about one universal female testosterone range. Testosterone declined progressively with age—approximately 1.4% per year—while the distribution of concentrations also changed. Rather than simply labeling testosterone “normal” or “abnormal,” the researchers developed an age-specific model that allows a woman’s testosterone concentration to be understood relative to other healthy women of approximately the same age.
This is valuable work, but understanding what the study actually measures is essential. It describes endogenous physiology: what testosterone concentrations naturally occur in untreated women. It does not establish the testosterone concentration that produces the greatest therapeutic benefit in a symptomatic woman receiving testosterone therapy. Those questions are related, but they are not interchangeable.
Physiologic Does Not Automatically Mean Therapeutically Optimal
A reference range describes what is observed within a population, whereas a therapeutic range asks what exposure to a treatment produces a desired clinical effect while maintaining an acceptable safety profile. This distinction exists throughout medicine, and testosterone therapy should not be exempt from it simply because testosterone is also an endogenous hormone.
Conventional guidelines remain cautious about this distinction. The International Society for the Study of Women’s Sexual Health (ISSWSH), for example, states that there is currently no established serum testosterone concentration that can be used as a therapeutic treatment target and generally recommends maintaining concentrations within the premenopausal physiologic range. That is an important limitation in our present knowledge, but saying that an optimal therapeutic concentration has not yet been established is very different from saying that there is no evidence relating testosterone exposure to clinical response. In fact, controlled dose-response studies provide some fascinating evidence.
What Happens When Researchers Actually Increase Testosterone?
One particularly important randomized dose-response study examined testosterone therapy in hysterectomized postmenopausal women receiving standardized estradiol therapy. Women were randomized to progressively increasing testosterone doses, producing mean nadir total testosterone concentrations of approximately 19 ng/dL with placebo and 78, 102, 128, and 210 ng/dL with progressively higher testosterone doses.
The numbers are striking because three of those experimental groups—78, 102, and 128 ng/dL—fall directly within the 70–150 ng/dL therapeutic range we have used clinically for approximately two decades. This does not validate 70–150 ng/dL as the universally optimal range, but it demonstrates that women have been prospectively studied at testosterone concentrations directly within this range.
Even more interesting was the relationship between testosterone exposure and clinical outcomes. Increasing free testosterone demonstrated significant associations with measures that included sexual function, sexual desire, arousal, frequency of sexual activity, lean body mass, and physical performance. The study therefore provides evidence for a biological concentration-response relationship rather than suggesting that the serum testosterone concentration is clinically irrelevant.
There is an important qualification. The strongest between-group improvements in several outcomes occurred at the highest exposure, where mean nadir total testosterone was approximately 210 ng/dL. Therefore, the study cannot be interpreted as proving that 78–128 ng/dL is the optimal therapeutic window. What it does show is that testosterone concentrations within and above our historical therapeutic range have been deliberately studied and that increasing androgen exposure can produce measurable changes in clinically meaningful outcomes.
Earlier Randomized Trials Tell a Similar Story
A major randomized trial by Braunstein and colleagues provides another important piece of the puzzle. Women received placebo or transdermal testosterone at 150, 300, or 450 micrograms per day. At 24 weeks, median total testosterone concentrations were approximately 18 ng/dL with placebo, 44.5 ng/dL with 150 μg/day, 91 ng/dL with 300 μg/day, and 122.5 ng/dL with 450 μg/day.
Again, the higher-dose treatment groups produced testosterone concentrations directly within the range we have historically used at The Hormone Zone. The 300-μg group, with a median total testosterone concentration of approximately 91 ng/dL, demonstrated significant improvement in sexual outcomes, while serum androgen concentrations showed relationships with several measures of sexual response. Importantly, pushing testosterone exposure still higher did not simply result in proportionally greater benefit, reinforcing the principle that testosterone therapy should not be a competition to achieve the highest possible laboratory value.
Other major testosterone trials in women have demonstrated similar patterns. The classic Shifren trial found greater sexual-function benefits with the 300-μg testosterone dose than with the lower dose, while the large APHRODITE trial involving more than 800 postmenopausal women also demonstrated significant improvement in satisfying sexual episodes with 300 μg/day testosterone. Taken together, these studies support the broader concept that testosterone exposure matters and that therapeutic benefit cannot necessarily be reduced to simply restoring a woman to the middle of an age-matched endogenous reference interval.
So Is 70–150 ng/dL “Normal”?
This is where terminology becomes extremely important. We would not describe 70–150 ng/dL as an age-adjusted physiologic range, particularly in light of the new Wainwright data. For many middle-aged and older women, concentrations within this range extend substantially above the endogenous testosterone distribution observed in untreated healthy women.
But that is not how we have historically used the range at The Hormone Zone. We have used 70–150 ng/dL as a clinically titrated therapeutic range, meaning that laboratory values are interpreted alongside symptoms, clinical response, SHBG, the broader hormonal environment, and evidence of unwanted androgenic effects. A physiologic reference range asks what testosterone concentrations naturally occur in untreated women of a particular age, whereas a therapeutic range asks what testosterone exposure may produce meaningful clinical benefit in a woman being treated without creating unacceptable adverse effects. Medicine should be careful not to confuse those two questions.
This distinction also helps reconcile what initially appears to be a contradiction in the literature. The 2026 Wainwright study suggests that a total testosterone of 90 or 100 ng/dL is well above the natural age-adjusted distribution for many middle-aged women. Yet randomized therapeutic trials have deliberately produced testosterone concentrations around 78, 91, 102, 122, and 128 ng/dL, with evidence of androgen-dependent effects. Both observations can be true because one body of research is describing natural physiology, while the other is studying pharmacologic therapy.
What the Evidence Does—and Does Not—Prove
Current research does not establish that every woman should have a testosterone concentration between 70 and 150 ng/dL. We still lack the ideal study in which large numbers of appropriately selected symptomatic women are randomized to specific serum testosterone targets—perhaps 30, 60, 90, 120, and 150 ng/dL—and then followed for sexual function, muscle mass, strength, bone health, mood, cognition, quality of life, cardiovascular outcomes, breast outcomes, and androgenic adverse effects. Until such studies are performed, it would be inappropriate to claim that any particular serum range has been definitively established as optimal.
At the same time, it would also be incomplete to imply that therapeutic testosterone concentrations above conventional age-adjusted reference ranges are unsupported by clinical research. Randomized dose-response studies have produced concentrations directly within the 70–150 ng/dL range, and those studies have demonstrated relationships between androgen exposure and sexual function, body composition, and physical performance. The evidence therefore supports continued investigation of therapeutic testosterone exposure while also making clear that long-term optimal targets and safety boundaries remain incompletely defined.
Treat the Woman, Not Just the Laboratory Range
After nearly two decades of prescribing testosterone to women, our clinical approach remains centered on the patient rather than an isolated laboratory number. A testosterone value by itself does not tell us whether a woman has regained sexual desire, feels stronger and more energetic, is maintaining muscle, or is experiencing unwanted effects from therapy. We consider symptoms, clinical response, total testosterone, SHBG, the broader hormonal environment, and appropriate safety monitoring rather than treating the laboratory number as the endpoint itself.
The goal is therefore not to chase testosterone higher, nor is it simply to force every woman into the statistical range of untreated women her age. The goal is to use hormone therapy thoughtfully to improve function and quality of life while continually evaluating benefit, tolerance, and safety.
This is also why we find the current moment in women’s hormone therapy so exciting. After decades of controversy, oversimplification, and in many cases therapeutic neglect, we are finally having a richer conversation about hormones throughout a woman’s lifespan. Estrogen, progesterone, and testosterone are increasingly being discussed not merely through the narrow lens of treating hot flashes, but within the much larger conversation surrounding sexual health, bone, muscle, metabolism, cognition, healthy aging, and quality of life.
We believe we may truly be entering a golden age of women’s hormone therapy, characterized by better research, better laboratory measurement, more individualized treatment, and a greater willingness to listen to women’s actual experiences. There is still much to learn, particularly regarding optimal testosterone dosing and long-term outcomes, but the renewed scientific attention is long overdue and enormously encouraging.
The new Wainwright study gives us a better map of natural female testosterone physiology, while the testosterone dose-response trials give us a different map of what happens when testosterone is used therapeutically. We need both maps. For this reason, rather than calling 70–150 ng/dL a physiologic replacement range, we believe a more scientifically accurate description of how we have used it at The Hormone Zone is a clinically titrated therapeutic testosterone range. After nearly 20 years of clinical experience, it is encouraging to see modern research increasingly asking many of the same questions that have guided our approach to women’s hormone therapy for years.
References
Wainwright E, Getreu N, Crawford L, et al. Redefining testosterone reference ranges for adult females. Journal of Endocrinological Investigation. 2026;49:2339–2349.
Braunstein GD, Sundwall DA, Katz M, et al. Safety and efficacy of a testosterone patch for the treatment of hypoactive sexual desire disorder in surgically menopausal women. Archives of Internal Medicine. 2005;165:1582–1589.
Huang G, Basaria S, Travison TG, et al. Testosterone dose-response relationships in hysterectomized women with or without oophorectomy.
Shifren JL, Braunstein GD, Simon JA, et al. Transdermal testosterone treatment in women with impaired sexual function after oophorectomy. New England Journal of Medicine. 2000.
Davis SR, Moreau M, Kroll R, et al. Testosterone for low libido in postmenopausal women not taking estrogen. New England Journal of Medicine. 2008.
Parish SJ, Simon JA, Davis SR, et al. International Society for the Study of Women’s Sexual Health Clinical Practice Guideline for the Use of Systemic Testosterone for Hypoactive Sexual Desire Disorder in Women. 2021.
Disclaimer: This article is for educational purposes only and is not intended as individualized medical advice. Testosterone therapy should be prescribed and monitored by a clinician experienced in hormone therapy.
