What Is Prasterone and How Does It Work in the Body?

Prasterone is the pharmaceutical name for dehydroepiandrosterone, better known as DHEA, the most abundant steroid hormone circulating in the human body. Its only FDA-approved formulation is an intravaginal insert used to treat painful sex caused by menopause-related tissue changes, but the molecule itself has been studied for a remarkably wide range of conditions, from autoimmune disease to fertility to cognitive decline. The gap between what prasterone is approved for and what people hope it can do is large, and the evidence across those uses varies enormously.

What Prasterone Actually Is

Your adrenal glands produce DHEA in large quantities starting around age six or seven, a developmental phase sometimes called adrenarche. Production peaks in your twenties and then begins a long, steady decline. By the time you reach your seventies or eighties, circulating DHEA levels can drop to roughly 10 to 20 percent of what they were at peak.{¹} This decline is sometimes called “adrenopause,” and it is one of the most dramatic age-related hormonal shifts in the human body.{²}

DHEA is not itself a potent hormone. It functions as a precursor, a raw material that individual cells in tissues throughout the body convert into androgens and estrogens as needed. This process, called intracrinology, means that the active sex hormones are made locally inside each cell, do their work there, and are then inactivated before being released into the bloodstream for disposal by the liver and kidneys.{³} This local-action concept matters a great deal for understanding why intravaginal prasterone can improve vaginal tissue without significantly raising hormone levels in the rest of the body.

The Approved Use for Menopause-Related Vaginal Symptoms

After menopause, declining estrogen causes the vaginal lining to thin, dry out, and lose elasticity. The medical term for this cluster of changes is vulvovaginal atrophy, and the most disruptive symptom for many women is dyspareunia, or pain during sex. Prasterone is approved in the United States as a daily intravaginal insert (6.5 mg) specifically for moderate to severe dyspareunia due to menopause.{⁴}

The clinical evidence behind this approval is solid. In combined data from multiple trials involving over 400 women treated with prasterone and roughly 260 on placebo, the prasterone group showed a large drop in the proportion of parabasal cells (a marker of tissue thinning), an increase in superficial cells (a marker of tissue health), and a meaningful decrease in vaginal pH, all highly significant statistically.{⁵} Separately, a trial focused on symptoms found that pain during sex dropped by about 46 percent more than placebo, and moderate-to-severe vaginal dryness decreased by about 42 percent beyond placebo, both after 12 weeks of daily use.{⁶}

A small open-label pilot study using vulvoscopic photography offered a particularly vivid illustration of what happens at the tissue level. Women using intravaginal prasterone showed visible reductions in vestibular redness and pallor over 20 weeks. By the final month of the study, sexual activity associated with pain had fallen from over 80 percent of encounters to about 8 percent.{⁷}

Why Systemic Hormone Levels Stay Low

One of the main concerns women and their doctors have about any hormone-related treatment after menopause is whether it will raise systemic estrogen or androgen levels, with the associated risks for breast cancer and cardiovascular disease. The intravaginal route of prasterone was specifically designed to exploit the intracrinology concept: DHEA enters vaginal cells, gets converted into the active hormones those cells need, and the metabolites that leave are already inactivated.

Studies tracking blood hormone levels in women using the 6.5 mg daily insert for 12 weeks found no significant change in average 24-hour serum estradiol or testosterone concentrations from baseline. Serum DHEA stayed within normal postmenopausal ranges, and downstream metabolites of both estrogens and androgens likewise remained at postmenopausal levels.{⁸} In one analysis, serum estradiol after 12 weeks of treatment measured about 3.4 pg/ml, actually about 19 percent below the average normal postmenopausal value, and serum estrone sulfate, a broad marker of estrogenic activity, was essentially identical to normal postmenopausal levels.{⁹}

This is a meaningful distinction from systemic estrogen therapy, where the goal is to raise circulating hormone levels. With intravaginal prasterone, the vaginal tissue gets what it needs while the rest of the body barely notices.

Prasterone After Breast Cancer Treatment

Women who have been treated for breast cancer and are taking aromatase inhibitors face a particularly cruel catch-22: the drugs that suppress estrogen to keep cancer at bay also devastate vaginal tissue, causing severe dryness and pain. Standard vaginal estrogen products are often considered off-limits for these patients because of theoretical concerns about even small systemic estrogen increases.

A pilot study (the VIBRA study) tested intravaginal prasterone in breast cancer survivors on aromatase inhibitors and found that mean serum estradiol remained very low, moving from 3.4 pg/ml at baseline to 4.3 pg/ml after six months, a change that was not statistically significant. Meanwhile, dyspareunia scores improved dramatically, and the Vaginal Health Index and sexual function scores both improved significantly.{¹⁰} This is preliminary data from a small study, and it would be premature to call intravaginal prasterone safe for all breast cancer survivors. But the pilot results have generated enough interest that larger trials are being planned, and some oncologists are already discussing it as a potential option when the alternative is untreated sexual dysfunction.

Adrenal Insufficiency and Well-Being

People with Addison’s disease or other forms of adrenal insufficiency lose nearly all adrenal DHEA production. Standard treatment replaces cortisol and sometimes aldosterone, but DHEA is not typically part of the regimen, leaving patients chronically deficient. Several trials have tested whether adding DHEA back improves quality of life.

A landmark trial published in the New England Journal of Medicine found that four months of DHEA replacement in women with adrenal insufficiency significantly improved overall well-being and reduced scores for depression and anxiety compared to placebo.{¹¹} A separate randomized trial in both men and women with Addison’s disease similarly reported improvements in self-esteem, mood, and fatigue, with the mood benefits being most noticeable in the evenings.{¹²}

However, when researchers tested longer-term DHEA replacement over 12 months in people with primary adrenal insufficiency, the results were more modest. Only one subscale of a standard quality-of-life questionnaire improved significantly, and there was no meaningful benefit for fatigue, cognitive function, or sexual function.{¹³} The short-term mood boost appears real, but whether DHEA replacement provides sustained, broad psychological benefits in adrenal insufficiency remains unsettled.

Lupus and Steroid-Sparing Effects

One of the more intriguing chapters in prasterone research involves systemic lupus erythematosus. Because lupus disproportionately affects women and DHEA has immune-modulating properties, researchers tested oral prasterone (200 mg daily) as an add-on therapy. In a large placebo-controlled trial, about 59 percent of prasterone-treated patients with clinically active lupus showed improvement or stabilization without deterioration, compared to roughly 45 percent on placebo.{¹⁴}

Perhaps more compelling was the effect on corticosteroid use. A separate trial found that women on oral prasterone were significantly more likely to sustain a reduction in their prednisone dose to 7.5 mg per day or less while still keeping their lupus under control.{¹⁵} Given that long-term corticosteroid use carries its own serious side effects, a treatment that helps patients taper their steroid dose is genuinely valuable. Despite these promising results, oral prasterone never achieved FDA approval for lupus and is not part of standard rheumatological care, partly because the effect sizes were modest and partly because pharmaceutical development stalled.

Bone Density in Older Adults

Because DHEA feeds into estrogen production, researchers have wondered whether supplementation might help prevent the bone loss that accelerates after menopause. The evidence here is consistently sex-specific: women get a small benefit, men do not.

A pooled analysis of four clinical trials found that women on DHEA gained about 1 percent in lumbar spine bone mineral density and about half a percent at the trochanter (part of the hip), while maintaining total hip density. Men saw no bone benefit at all, though they did lose a small amount of fat mass.{¹⁶} An individual trial, the DAWN study, confirmed the pattern: a positive effect on lumbar spine density in women after 12 months, but no effect at the hip, femoral neck, or total body, and nothing significant in men.{¹⁷}

A 1 percent improvement in spine density over a year is real but small. Standard osteoporosis medications typically produce gains several times that size. DHEA supplementation is not a substitute for established bone treatments, though it may contribute a modest add-on effect in women.

Cognition and the Anti-Aging Hype

The dramatic age-related decline in DHEA levels has fueled persistent speculation that replenishing it might slow cognitive aging or even stave off dementia. This is the area where the gap between hope and evidence is widest.

A Cochrane systematic review, the gold standard for evidence synthesis, found that the limited controlled trial evidence did not support any beneficial effect of DHEA supplementation on cognitive function in healthy middle-aged or elderly people.{¹⁸} The DAWN trial, which specifically tested cognitive outcomes alongside bone and well-being endpoints in healthy older adults, found no difference between DHEA and placebo on any cognitive measure over a year of supplementation.{¹⁹}

A review exploring the disconnect between the promising animal data and the disappointing human results pointed to an important biological difference: rodents, the animals most commonly used in DHEA research, produce almost no DHEA naturally. Giving them DHEA creates a dramatic change in brain chemistry. Humans, by contrast, have high circulating DHEA throughout life, and adding more on top of what remains in older adults may not move the needle the same way.{²⁰} The researchers behind the DAWN trial were blunt in their conclusion: DHEA supplementation should not be recommended for cognitive or well-being purposes in the general older population.

Fertility and IVF

DHEA supplementation has become popular among fertility clinics treating women with diminished ovarian reserve, a condition where the ovaries respond poorly to stimulation during IVF. The initial enthusiasm came from observational data suggesting higher pregnancy rates and shorter time to conception in supplemented women. One early cohort study reported cumulative clinical pregnancy rates of about 28 percent with DHEA versus about 11 percent in controls.{²¹}

The picture becomes muddier with more rigorous study designs. A meta-analysis that included a range of study types found that DHEA use was associated with roughly 80 percent higher odds of pregnancy and a significant reduction in miscarriage likelihood.{²²} But a separate meta-analysis that restricted its analysis to randomized controlled trials only found no statistically significant improvement in clinical pregnancy rates or live birth rates.{²³}

This is a classic situation in medicine where the initial excitement from less rigorous data gets tempered by tighter studies. Many fertility specialists still recommend DHEA supplementation for poor responders on the grounds that it is low-risk and the observational signal is encouraging, but the evidence from properly randomized trials has not yet confirmed the benefit. If you are offered DHEA as part of a fertility protocol, it is reasonable to try, but be aware that the strongest study designs have not found a clear win.

Erectile Function in Men

Because DHEA is a precursor to testosterone, oral supplementation has been explored for erectile dysfunction. One early placebo-controlled study reported that men taking DHEA had higher scores across all domains of the International Index of Erectile Function.{²⁴} But a later randomized trial that directly compared DHEA, testosterone, and placebo in men with low androgen levels and sexual dysfunction found no significant differences between any of the groups on sexual interest or erectile function using four different assessment instruments.{²⁵}

A review of the field concluded that while some trials in healthy middle-aged and elderly men reported improvements in various aspects of well-being, the evidence for DHEA specifically improving erectile function remains inconsistent.{²⁶} If you are dealing with erectile difficulties, established treatments with stronger evidence bases exist, and DHEA supplementation is not a reliable substitute.

Cardiovascular Effects

Arterial stiffness is one of the hallmarks of cardiovascular aging, and one trial in healthy older adults found that 12 months of DHEA supplementation reduced a measure called the augmentation index by about 6 units compared to placebo. This improvement coincided with decreases in two inflammatory markers, TNF-alpha and IL-6.{²⁷} However, a separate randomized crossover trial testing DHEA in patients with adrenal insufficiency found no effect on arterial stiffness, central blood pressure, or endothelial function, despite successfully normalizing blood DHEA levels. The only detectable metabolic change was a small decrease in HDL cholesterol, which if anything is unfavorable.{²⁸}

These conflicting results are typical of the cardiovascular DHEA literature. The difference may reflect the populations studied — healthy aging adults versus people with specific diseases — but there is currently no solid basis for recommending DHEA supplementation for cardiovascular protection.

Immune Modulation and Inflammation

DHEA appears to have genuine immune-modulating properties that go beyond its role as a hormone precursor. Laboratory and animal studies have shown that it can both stimulate certain immune functions and counteract the immune-suppressing effects of cortisol.{²⁹} More recent cell-culture work has demonstrated that DHEA and its sulfated form can reduce inflammatory signaling molecules in liver cells, including markers associated with fibrosis and chronic inflammation.{³⁰}

An important caveat applies here: much of the immune research on DHEA was done in rodents, and as mentioned earlier, rodents have negligible natural DHEA production. The effects seen in a DHEA-naive mouse may not translate directly to a human who already has substantial circulating DHEA, even at reduced older-age levels. The immune angle helps explain the lupus results discussed earlier and keeps DHEA interesting to immunology researchers, but it has not yet led to approved immunological therapies.

Skin Changes and Side Effects

Because DHEA feeds into both estrogen and androgen production, supplementation can affect the skin in both desirable and undesirable ways. A year-long study of oral DHEA at 50 mg daily in older adults found improvements in sebum production, skin hydration, pigmentation, and epidermal thickness, with the researchers noting no harmful consequences at that dose. A separate study testing a 1 percent DHEA cream applied topically to the face and hands of postmenopausal women found improvements in skin brightness and a reduction in the papery, thin appearance associated with hormonal skin aging.{³¹}

The flip side of these benefits is predictable from the hormone pathway. Excess DHEA can cause oily skin, acne, and increased facial or body hair growth in women, and occasionally breast tenderness. These are dose-dependent side effects, more common with oral supplementation at higher doses than with the low-dose intravaginal formulation approved for dyspareunia.

An Unusual Evolutionary Story

Prasterone has an oddly specific place in primate evolution. The postnatal rise in DHEA production, called adrenarche, is unique to humans and African great apes. In both species, a specialized layer of the adrenal gland called the zona reticularis develops at about three to four years of age and begins pumping out DHEA. Research has linked this developmental surge in DHEA to the maturation of specific brain regions in children between the ages of roughly four and twelve, including areas involved in decision-making and social cognition.{³²}

Most mammals do not produce meaningful amounts of DHEA at all. This makes the molecule something of an evolutionary novelty, and it raises questions about whether its age-related decline in humans is a benign feature of aging or a genuine deficiency that contributes to disease. That question is not purely academic — it sits at the heart of the debate over whether healthy older adults should supplement with DHEA. The decline is dramatic and universal, but as the cognitive and cardiovascular evidence shows, simply refilling the tank does not reliably reverse the changes associated with aging. The brain regions that DHEA helped build during childhood may no longer respond to it the same way decades later.

Navigating the Supplement Market

Outside its FDA-approved intravaginal formulation (sold under the brand name Intrarosa), DHEA is widely available over the counter in the United States as a dietary supplement. This creates a confusing situation: the same molecule is a prescription drug in one form and an unregulated supplement in another. In many other countries, including Canada and most of Europe, DHEA requires a prescription in any form.

The supplement market means that people can and do self-prescribe oral DHEA at doses ranging from 25 mg to 100 mg or more daily, often based on the anti-aging marketing that surrounds the molecule. The evidence reviewed above should give pause. For the approved vaginal indication, the data is strong: local tissue improvement with minimal systemic exposure. For oral supplementation aimed at cognition, energy, sexual function, or general anti-aging, the controlled trial evidence ranges from thin to negative. The adrenal insufficiency data is the most supportive case for oral DHEA, and even there, long-term benefits remain uncertain.

People taking oral DHEA should also be aware of its potential to interact with hormone-sensitive conditions. Because the body converts DHEA into both estrogens and androgens, supplementation could theoretically affect conditions like hormone-receptor-positive breast cancer, polycystic ovary syndrome, or endometriosis. The intravaginal formulation’s safety profile is better characterized precisely because the systemic exposure is negligible, but even that formulation requires careful discussion with a physician in the context of estrogen-sensitive cancers.