Pangenomic changes induced by DHEA in the skin of postmenopausal women

Hormonal Effects on Asthma, Rhinitis, and Eczema

Hormones significantly influence the pathogenesis of asthma, rhinitis, and eczema. This review aims to summarize relevant clinical considerations for practicing allergists and immunologists. The first section reviews the effects of sex hormones: estrogen, progesterone, and testosterone. The second concerns insulin production in the context of type 1 and type 2 diabetes. The third concludes with a discussion of thyroid and adrenal pathology in relationship to asthma, rhinitis, and eczema.

Clinical and biological impact of the exposome on the skin

The skin exposome is defined as the totality of environmental exposures over the life course that can induce or modify various skin conditions. Here, we review the impact on the skin of solar exposure, air pollution, hormones, nutrition and psychological factors. Photoageing, photocarcinogenesis and pigmentary changes are well-established consequences of chronic exposure of the skin to solar radiation. Exposure to traffic-related air pollution contributes to skin ageing. Particulate matter and nitrogen dioxide cause skin pigmentation/lentigines, while ozone causes wrinkles and has an impact on atopic eczema. Human skin is a major target of hormones, and they exhibit a wide range of biological activities on the skin. Hormones decline with advancing age influencing skin ageing. Nutrition has an impact on numerous biochemical processes, including oxidation, inflammation and glycation, which may result in clinical effects, including modification of the course of skin ageing and photoageing. Stress and lack of sleep are known to contribute to a pro-inflammatory state, which, in turn, affects the integrity of extracellular matrix proteins, in particular collagen. Hormone dysregulation, malnutrition and stress may contribute to inflammatory skin disorders, such as atopic dermatitis, psoriasis, acne and rosacea.

Vaginal dehydroepiandrosterone compared to other methods of treating vaginal and vulvar atrophy associated with menopause

During the menopause, a fall in estrogen levels often leads to many unfavorable symptoms, including changes in the vascular and urogenital systems, in mood, and sleep. The symptoms of vulvovaginal atrophy are especially troublesome for menopausal women. These symptoms not only disturb the sexual sphere, but also functioning at work and in the family. Based on the literature, a review of contemporary methods of management in the case of symptoms of vulvar atrophy in menopausal women has been performed. The current methods of treating vulvovaginal atrophy in menopausal women are described. The pharmacology of the available dehydroepiandrosterone (DHEA) preparations, both oral and vaginal, was briefly analyzed. Own experiences of using DHEA are presented. Vaginal DHEA has been found to be an effective and safe treatment in menopausal women with symptoms of vaginal atrophy.

The role of bioidentical hormone replacement therapy in anti-aging medicine: a review of the literature

The changes in skin and overall appearance that occur with increasing age can be partly attributed to declining hormone levels. While hormonal deficiencies are most commonly associated with postmenopausal females, males are also subject to age-related testosterone decline and may benefit from replacement of deficient hormones. However, great disparities exist between the recommendations of scientific societies and actual use of hormone supplements in aging patients. The purpose of this literature review is to discuss the role of hormones in the aging process of the skin, explain the safety profile of hormone replacement therapy, specifically discussing the superiority of bioidentical hormones, and highlight the benefits of hormone replacement in anti-aging of the skin. In summary, this literature review suggests that hormone replacement with bioidentical hormones is a safe and effective way to prevent skin aging.

The Roles of Sex Hormones in the Course of Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by T helper 2 cell (Th2)-shifted abnormal immunity, skin barrier impairment, and pruritus. The prevalence of AD in childhood is slightly higher in boys than in girls; after puberty, the sexual difference is reversed. The female preponderance in all generations exists in intrinsic AD with enhanced Th1 activity and nickel allergy, lacking increased serum IgE or filaggrin mutation. AD is often deteriorated before menstruation. We review the effects of sex hormones on immune responses and skin permeability barrier and propose possible hypotheses for the above phenomena. After puberty, the immune responses of patients are remarkably influenced by sex hormones. Estrogen and progesterone enhance the activities of Th2/regulatory T cell (Treg) but suppress Th1/Th17. Androgens suppress Th1/Th2/Th17 and induce Treg. The skin permeability barrier is fortified by estrogen but is impaired by progesterone and androgens. Dehydroepiandrosterone suppresses Th2 but enhances Th1. The amount of steroid sulfatase converting dehydroepiandrosterone sulfate to dehydroepiandrosterone is higher in women than in men, and thus, women might be more susceptible to the influence of dehydroepiandrosterone. The balance of modulatory effects of sex hormones on immune responses and skin barrier might regulate the course of AD.

Potential prevention by oral DHEA of superficial tears in elderly atrophic skin

Oral DHEA improves skin hydration and sebum production as well as bone mineral density in older patients while limiting progression of their skin atrophy. Topical DHEA cream stimulates local collagen production. Trials of oral DHEA should be undertaken to examin their potential for preventing tears in fragile aging skin.

Dehydroepiandrosterone for women in the peri- or postmenopausal phase

BACKGROUND

During menopause a decreasing ovarian follicular response generally causes a fluctuation and eventual decrease in estrogen levels. This can lead to the development of various perimenopausal and postmenopausal symptoms (for example hot flushes, night sweats, vaginal dryness). Dehydroepiandrosterone (DHEA) is one of the main precursors of androgens, which in turn are converted to testosterone and estrogens. It is possible that the administration of DHEA may increase estrogen and testosterone levels in peri- and postmenopausal women to alleviate their symptoms and improve general wellbeing and sexual function (for example libido, dyspareunia, satisfaction). Treatment with DHEA is controversial as there is uncertainty about its effectiveness and safety. This review should clearly outline the evidence for DHEA in the treatment of menopausal symptoms and evaluate its effectiveness and safety by combining the results of randomised controlled trials.

OBJECTIVES

To assess the effectiveness and safety of administering DHEA to women with menopausal symptoms in the peri- or postmenopausal phase.

SEARCH METHODS

The databases that we searched (3 June 2014) with no language restrictions applied were the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS. We also searched conference abstracts and citation lists in the ISI Web of Knowledge. Ongoing trials were searched in the trials registers. Reference lists of retrieved articles were checked.

SELECTION CRITERIA

We included randomised controlled trials comparing any dose and form of DHEA by any route of administration versus any other active intervention, placebo or no treatment for a minimal treatment duration of seven days in peri- and postmenopausal women.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data after assessing eligibility for inclusion and quality of studies. Authors were contacted for additional information.

MAIN RESULTS

Twenty-eight trials with 1273 menopausal women were included in this review. Data could be extracted from 16 trials to conduct the meta-analysis. The overall quality of the studies was moderate to low with the majority of studies that were included in the meta-analysis having reasonable methodology. Compared to placebo, DHEA did not improve quality of life (standardised mean difference (SMD) 0.16, 95% confidence interval (CI) -0.03 to 0.34, P = 0.10, 8 studies, 287 women (132 from parallel and 155 from crossover trials), I² = 0%, moderate quality evidence; one trial of the nine that reported on this outcome was removed in a sensitivity analysis as it was judged to be at high risk of bias). DHEA was found to be associated with androgenic side effects (mainly acne) (odds ratio (OR) 3.77, 95% CI 1.36 to 10.4, P = 0.01, 5 studies, 376 women, I² = 10%, moderate quality evidence) when compared to placebo. No associations were found with other adverse effects. It was unclear whether DHEA affected menopausal symptoms as the results from the trials were inconsistent and could not easily be pooled to provide an overall effect due to different types of measurement (for example continuous, dichotomous, change and end scores). DHEA was found to improve sexual function (SMD 0.31, 95% CI 0.07 to 0.55, P = 0.01, 5 studies, 261 women (239 women from parallel trials and 22 women from crossover trials), I² = 0%; one trial judged to be at high risk of bias was removed during sensitivity analysis) compared to placebo.There was no difference in the acne associated with DHEA when comparing studies that used oral DHEA (OR 2.16, 95% CI 0.47 to 9.96, P = 0.90, 3 studies, 136 women, I² = 5%, very low quality evidence) to one study that used skin application of DHEA (OR 2.74, 95% CI 0.10 to 74.87, P = 0.90, 1 study, 22 women, very low quality evidence). The effects did not differ for sexual function when studies using oral DHEA (SMD 0.11, 95% CI -0.13 to 0.35, P = 0.36, 5 studies, 340 women, I² = 0) were compared to a study using intravaginal DHEA (SMD 0.42, 95% CI 0.03 to 0.81, 1 study, 218 women). Test for subgroup differences: Chi² = 1.77, df = 1 (P = 0.18), I² = 43.4%. Insufficient data were available to assess quality of life and menopausal symptoms for this comparison.There were insufficient data available to compare the effects of DHEA to hormone therapy (HT) for quality of life, menopausal symptoms, and adverse effects. No large differences in treatment effects were found for sexual function when comparing DHEA to HT (mean difference (MD) 1.26, 95% CI -0.21 to 2.73, P = 0.09, 2 studies, 41 women, I² = 0%).

AUTHORS' CONCLUSIONS

There is no evidence that DHEA improves quality of life but there is some evidence that it is associated with androgenic side effects. There is uncertainty whether DHEA decreases menopausal symptoms, but DHEA may slightly improve sexual function compared with placebo.

DHEA - a precursor of ERβ ligands

What is DHEA and why is there so much public interest in this steroid which has been touted as the fountain of youth and is supposed to have all kinds of health benefits? Endocrinologists have been fascinated with DHEA for a long time because of its high production in the fetal adrenals and its continued high levels until the 7th decade of life. Yet there is still little agreement about its physiological functions. In its simplest terms endocrinology is the communication between at least three organs: one sends a message, one releases a hormone into the blood in response to the message and one responds to the hormone. DHEA is produced by a specific zone of the adrenal cortex, the zona reticularis, whose sole function is to produce this steroid. Glucocorticoids and mineralocorticoids which are C21 steroids are produced in two other zones of the adrenal cortex called the zona fasicularis and the zona glomerulosa, respectively. Being C21 steroids, they cannot be synthesized from DHEA which is a C19 steroid. To date there is no known hormone which specifically stimulates the zona reticularis and there is no known specific receptor for DHEA. Thus DHEA does not qualify as a hormone. DHEA could have autocrine or paracrine effects but, so far, there is no known effect of DHEA on either the cells of the zona glomerulosa or the zona fasicularis. Of course DHEA could have functions as a local precursor of androgens or estrogens and many studies have reported on the beneficial effects of transdermal or transvaginal administration of DHEA in postmenopausal women. This review will consider two of the potential functions of DHEA as a precursor of estrogen receptor beta (ERβ) ligands.

Stem cells and aberrant signaling of molecular systems in skin aging

The skin is the body's largest organ and it is able to self-repair throughout an individual's life. With advanced age, skin is prone to degenerate in response to damage. Although cosmetic surgery has been widely adopted to rejuvinate skin, we are far from a clear understanding of the mechanisms responsible for skin aging. Recently, adult skin-resident stem/progenitor cells, growth arrest, senescence or apoptotic death and dysfunction caused by alterations in key signaling genes, such as Ras/Raf/MEK/ERK, PI3K/Akt-kinases, Wnt, p21 and p53, have been shown to play a vital role in skin regeneration. Simultaneously, enhanced telomere attrition, hormone exhaustion, oxidative stress, genetic events and ultraviolet radiation exposure that result in severe DNA damage, genomic instability and epigenetic mutations also contribute to skin aging. Therefore, cell replacement and targeting of the molecular systems found in skin hold great promise for controlling or even curing skin aging.

Enhanced cutaneous bioavailability of dehydroepiandrosterone mediated by nano-encapsulation

Polymeric nanocarriers, especially nanospheres (NSs) and nanocapsules (NCs), can promote the penetration of their cargo through the skin barrier, towards improved cutaneous bioavailability. Dehydroepiandrosterone (DHEA), an endogenous hormone exhibiting poor aqueous solubility, was shown to be effective in modulating skin-aging processes following topical application. In this study, we designed adequate DHEA preparations, in an attempt to enable local delivery of the active ingredient to the viable skin layers. In addition, the potential efficiency of DHEA NCs on dermal collagen synthesis was evaluated. Cryo-TEM observations and thermal analysis indicated that DHEA was successfully incorporated within a stable NC-based delivery system. Moreover, higher [(3)H]-DHEA levels were recorded in the viable skin layers following different incubation periods of NCs on excised pig skin specimens as compared to DHEA oil solution (free molecule). Furthermore, significantly higher (4-fold) skin flux values were observed for the DHEA NCs as compared to the values elicited by the oil control solution. Finally, collagen synthesis in human skin organ culture, assessed by the incorporation of [(3)H]-proline, was up to 42% higher for DHEA NCs 48h post-topical application than for the untreated specimens. Overall, these results suggest that poly lactic-co-glycolic acid (PLGA)-based NCs have promising potential to be used topically for various skin disorders.

Hormonal therapy of intrinsic aging

Intrinsic skin aging represents the biological clock of the skin cells per se and reflects the reduction processes that are common in internal organs. The reduced secretion of the pituitary, adrenal glands, and the gonads contributes to characteristic aging-associated body and skin phenotypes as well as behavior patterns. Our knowledge of whether there is a direct or indirect connection between hormonal deficiency and skin aging still remains limited. In females, serum levels of 17β-estradiol, dehydroepiandrosterone, progesterone, growth hormone (GH), and its downstream hormone insulin-like growth factor I (IGF-I) are significantly decreased with increasing age. In males, serum levels of GH and IGF-I decrease significantly, whereas it can decrease in late age in a part of the population. Hormones have been shown to influence skin morphology and functions, skin permeability, wound healing, sebaceous lipogenesis, and the metabolism of skin cells. Prevention of skin aging by estrogen/progesterone replacement therapy is effective if administered early after menopause and influences intrinsically aged skin only. Vitamin D substitution and antioxidant treatment may also be beneficial. Replacement therapy with androgens, GH, IGF-I, progesterone, melatonin, cortisol, and thyroid hormones still remains controversial.

Dehydroepiandrosterone reduces preadipocyte proliferation via androgen receptor

Several studies have suggested that both testosterone and dehydroepiandrosterone (DHEA) have weight-reducing and antidiabetic effects, especially in rodent studies; however, the precise mechanism of their action remains unclear. Here, we investigated the effect of DHEA on cell growth in adipose tissue. The appearance of senescence-associated β-galactosidase in stromal vascular fraction (SVF) isolated from Otsuka Long-Evans Tokushima fatty rats, an animal model of inherent obese type 2 diabetes, was prevented by DHEA administration. Next, the effects of DHEA and testosterone were compared in vivo and in vitro to evaluate whether these hormones influence cell growth in adipose tissue. Both DHEA and testosterone reduced body weight and epididymal fat weight equivalently when administered for 4 wk. To assess the effect of DHEA and testosterone on cell growth in adipose tissue, 5-bromo-2'-deoxyuridine (BrdU) uptake by SVF was measured. Quantification analysis of BrdU uptake by examining DNA isolated from each SVF revealed that treatment with DHEA and testosterone reduced cell replication. These results indicated that DHEA- and testosterone-induced decreased adiposity was associated with reduced SVF growth. Incubation with DHEA and testosterone equally decreased BrdU uptake by 3T3-L1 preadipocytes. Pretreatment with the androgen receptor (AR) inhibitor flutamide, but not the estrogen receptor inhibitor fulvestrant, abolished these effects. Knockdown of AR with siRNA also inhibited DHEA-induced decreases in BrdU uptake. These results suggest that DHEA-induced growth suppression of preadipocytes is mediated via AR. Therefore, both DHEA and testosterone similarly decrease adipocyte growth possibly via a common mechanism.

Oxidative metabolism of dehydroepiandrosterone (DHEA) and biologically active oxygenated metabolites of DHEA and epiandrosterone (EpiA)--recent reports

Dehydroepiandrosterone (DHEA) is a multifunctional steroid with a broad range of biological effects in humans and animals. DHEA can be converted to multiple oxygenated metabolites in the brain and peripheral tissues. The mechanisms by which DHEA exerts its effects are not well understood. However, evidence that the effects of DHEA are mediated by its oxygenated metabolites has accumulated. This paper will review the panel of oxygenated DHEA metabolites (7, 16 and 17-hydroxylated derivatives) including a number of 5α-androstane derivatives, such as epiandrosterone (EpiA) metabolites. The most important aspects of the oxidative metabolism of DHEA in the liver, intestine and brain are described. Then, this article reviews the reported biological effects of oxygenated DHEA metabolites from recent findings with a specific focus on cancer, inflammatory and immune processes, osteoporosis, thermogenesis, adipogenesis, the cardiovascular system, the brain and the estrogen and androgen receptors.

The relationship between androgens, regulators of collagen metabolism, and Peyronie's disease: a case control study

INTRODUCTION

Changes in collagen metabolism have been postulated to play a pivotal role in the pathogenesis of Peyronie's Disease (PD). Androgens such as dehydroepiandrosterone sulfate (DHEA-S) and testosterone influence collagen metabolism by modulating the activity of matrix metalloproteases (MMP) and tissue inhibitors of metalloproteases (TIMP).

AIM

The aim of this study was to evaluate the interrelationship between androgens (DHEA-S and testosterone), key regulators of collagen metabolism such as insulin-like growth factor (IGF) 1 and IGF Binding Protein 3 (IGF-BP3), the MMP/TIMP system, and PD.

METHODS

Age matched PD patients (14) and healthy men (10) who acted as controls were recruited. Blood samples were collected from all subjects in the early morning hours after an overnight fast.

MAIN OUTCOME MEASURES

Serum levels of testosterone, sex hormone binding globulin, DHEA-S, 3-α-androstanediol glucuronide, pro-MMP-1, MMP-1, MMP-2, TIMP-1, TIMP-2, IGF-1 and IGF-BP3 were measured in both groups. Statistical methods included univariate, bivariate, and multivariate regression models.

RESULTS

Levels of DHEA-S (114.5 vs. 169.5 µg/dL; p = 0.03), IGF-BP3 (2.96 vs. 3.79 µg/mL; p = 0.01), and TIMP-1 (173.1 vs. 195 ng/mL; p = 0.01) were significantly lower in PD patients. In contrast, the level of TIMP-2 (102 vs. 85 ng/mL; p = 0.001) was significantly lower in the control group. Using stepwise regression analysis, only TIMP-2 (p < 0.001) and DHEA-S (p = 0.04) were significantly related to PD in the final model (R(2) = 0.63). TIMP-1 and DHEA-S (r = 0.55, p < 0.05) were positively correlated in the PD group, whereas IGF-1 and testosterone (r = -0.54, p < 0.05), and IGF-BP3 and testosterone (r = -0.68, p < 0.05) were negatively correlated in PD patients.

CONCLUSIONS

Our findings suggest that decreased levels of adrenal androgens may be implicated in the pathogenesis of PD. The mechanism and clinical relevance of this observation remain to be established.

Cutaneous resonance running time varies with age, body site and gender in a normal Chinese population

BACKGROUND/OBJECTIVES

One phenomenon of skin aging is loss of cutaneous elasticity. Measurement of cutaneous resonance running time (CRRT) is a method to assess skin elasticity. Yet, information regarding the directional changes of CRRT associated with age, body sites and gender is not yet available. In the present study, we assessed whether changes in CRRT vary with age, body sites and gender in a normal Chinese population.

METHODS

A Reviscometer was used to measure CRRTs in various directions on the left dorsal hand, the forehead and the left canthus of 806 normal Chinese volunteers, aged 2.5-94 years.

RESULTS

With aging, CRRTs decreased in all directions on the hand, the forehead and the canthus. A more dramatic reduction in CRRTs on the forehead and the canthus was observed in both the 2-8 and the 3-9 o'clock directions. CRRTs in males aged 11-20 years were longer than those in females in some directions on all three body sites. Females aged between 21 years and 40 years showed longer CRRTs than males in some directions of the hand. There were no gender differences in subjects aged 0-10 (except on the canthus) and those over 80 years old.

CONCLUSION

CRRTs vary with age, body sites and gender.

Skin responses to topical dehydroepiandrosterone: implications in antiageing treatment?

BACKGROUND

Although low dehydroepiandrosterone (DHEA) is suspected to have a role in skin ageing, little information is available on the mechanisms potentially involved.

OBJECTIVES

To obtain information on androgen receptor (AR) and procollagen expression in ageing skin during DHEA treatment.

METHODS

A placebo-controlled, randomized, prospective study was performed with 75 postmenopausal women aged 60-65 years. The women were treated twice daily for 13 weeks with 3·0 mL of placebo or 0·1%, 0·3%, 1% or 2% DHEA cream applied on the face, arms, back of hands, upper chest and right thigh where 2-mm biopsies were collected before and after treatment.

RESULTS

Although the overall structure of the epidermis was not significantly affected at the light microscopy level, AR expression examined by immunocytochemistry was markedly increased by DHEA treatment. In the dermis, the expression levels of procollagen 1 and 3 mRNA estimated by in situ hybridization were increased by DHEA treatment. In addition, the expression of heat shock protein (HSP) 47, a molecule believed to have chaperone-like functions potentially affecting procollagen biosynthesis, was also found by immunocytochemistry evaluation to be increased, especially at the two highest DHEA doses.

CONCLUSION

These data suggest the possibility that topical DHEA could be used as an efficient and physiological antiageing skin agent.

Effect of long-term topical application of dehydroepiandrosterone (DHEA) and oral estrogens on morphology, cell proliferation, procollagen A1 and androgen receptor levels in rat skin

BACKGROUND

After cessation of estrogen secretion by the ovaries at menopause, all estrogens and almost all androgens acting in the skin of postmenopausal women are synthesized locally from dehydroepiandrosterone (DHEA), a prohormone of adrenal origin that progressively declines with age.

OBJECTIVE

To better understand the effects of DHEA on the skin, ovariectomized (OVX) rats were treated for 9 months with local topical application of DHEA compared with oral conjugated equine estrogens.

MATERIALS AND METHODS

Morphological evaluation, immunohistochemistry for androgen receptor (AR) and Cdc47 proliferation marker, and in situ hybridization for procollagen A1 were performed on dorsal skin.

RESULTS

Local topical DHEA application increased the thickness of the granular cell layer and total epidermis in OVX animals, whereas systemic estrogens had no significant effect. Although DHEA did not affect total dermal thickness, a 190% increase in dermal procollagen A1 mRNA was observed. Moreover, DHEA treatment decreased hypodermal thickness by 47% and increased skin muscle thickness by 58%. In the epidermis, DHEA induced a non-significant increase in cell proliferation, whereas AR labeling was increased in both the epidermis and dermis by DHEA.

CONCLUSIONS

Although estrogens did not significantly modify any of the above-mentioned parameters, the androgenic action of DHEA induced significant changes in all skin layers, without any sign of toxicity or lack of tolerance to DHEA after a 9-month local application of 4% (80 mg/kg) DHEA on the skin.

High internal consistency and efficacy of intravaginal DHEA for vaginal atrophy

Following the compelling data obtained in a pivotal phase III clinical trial performed in 218 postmenopausal women suffering from vaginal atrophy who received daily intravaginal 0.25, 0.5 or 1.0% DHEA (dehydroepiandrosterone) ovules for 12 weeks, we have performed analysis of the four co-primary objectives at each site of that multicentre U.S. and Canadian trial. Comparison was made of the change in percentage of parabasal and superficial cells, vaginal pH and severity of the most bothersome symptom. The site-by-site (seven sites) analysis has shown that 10-13 women per group are generally sufficient to obtain a significant or highly statistically significant decrease in vaginal pH and percentage of parabasal cells and increased percentage of superficial cells at p values ranging from 0.02 to <0.0001. For vaginal pain as the most bothersome symptom, a statistically significant difference from baseline was found at six out of seven sites. The exceptionally high consistency between all sites in this phase III study and high potency of the compound permit to obtain a clinically and statistically significant to highly significant effect of treatment on all parameters of vaginal atrophy with the 0.5% DHEA daily intravaginal dose which does not significantly affect the serum levels of oestrogens, thus avoiding systemic risks.

DHEA, important source of sex steroids in men and even more in women

A major achievement from 500 million years of evolution is the establishment of a high secretion rate of dehydroepiandrosterone (DHEA) by the human adrenal glands coupled with the indroduction of menopause which stops secretion of estrogens by the ovary. Cessation of estrogen secretion at menopause eliminates the risks of endometrial hyperplasia and cancer which would result from non-opposed estrogen stimulation during the post-menopausal years. In fact, from the time of menopause, DHEA becomes the exclusive and tissue-specific source of sex steroids for all tissues except the uterus. Intracrinology, a term coined in 1988, describes the local formation, action and inactivation of sex steroids from the inactive sex steroid precursor DHEA. Over the past 25 years most, if not all, the genes encoding the human steroidogenic and steroid-inactivating enzymes have been cloned and sequenced and their enzymatic activity characterized. The problem with DHEA, however, is that its secretion decreases from the age of 30 years and is already decreased, on average, by 60% at time of menopause. In addition, there is a large variability in the circulating levels of DHEA with some post-menopausal women having barely detectable serum concentrations of the steroid while others have normal values. Since there is no feedback mechanism controlling DHEA secretion within 'normal' values, women with low DHEA will remain with such a deficit of sex steroids for their remaining lifetime. Since there is no other significant source of sex steroids after menopause, one can reasonably believe that low DHEA is involved, in association with the aging process, in a series of medical problems classically associated with post-menopause, namely osteoporosis, muscle loss, vaginal atrophy, fat accumulation, hot flashes, skin atrophy, type 2 diabetes, memory loss, cognition loss and possibly Alzheimer's disease. A recent randomized, placebo-controlled study has shown that all the signs and symptoms of vaginal atrophy, a classical problem recognized to be due to the hormone deficiency of menopause, can be rapidly improved or corrected by local administration of DHEA without systemic exposure to estrogens. In addition, the four domains of sexual dysfucntion are improved. For the other problems of menopause, although similar large scale, randomized and placebo-controlled studies usually remain to be performed, the available evidence already strongly suggests that they could be improved, corrected or even prevented by exogenous DHEA. In men, the contribution of adrenal DHEA to the total androgen pool has been measured at 40% in 65-75-year-old men. Such data stress the necessity of blocking both the testicular and adrenal sources of androgens in order to achieve optimal benefits in prostate cancer therapy. On the other hand, the comparable decrease in serum DHEA levels observed in both sexes has less consequence in men who continue to receive a practically constant supply of testicular sex steroids during their whole life. In fact, in men, the appearance of hormone-deficiency symptoms common to women is observed at a later age and with a lower degree of severity. Consequently, DHEA replacement has shown much more easily measurable beneficial effects in women. Most importantly, despite the non-scientific and unfortunate availability of DHEA as a food supplement in the United States, a situation that discourages rigorous clinical trials on the crucial physiological and therapeutic role of DHEA, no serious adverse event related to DHEA has ever been reported in the world literature (thousands of subjects exposed) or in the monitoring of adverse events by the FDA (millions of subjects exposed), thus indicating, as expected from its known physiology, the excellent safety profile of DHEA. With today's knowledge, one can reasonably suggest that DHEA offers the promise of a safe and efficient replacement therapy for the multiple problems related to hormone deficiency after menopause without the risks associated with estrogen-based or any other treatments.