Quality Control of Dehydroepiandrosterone Dietary Supplement Products

To the Editor.— Several steroidal hormone dehydroepiandrosterone (DHEA) commercial products have become available in the United States as so-called dietary supplements. However, DHEA is not a food; it does not occur naturally in the human food chain, and no foodstuff can mimic the physiologic or pharmacological consequences evoked by DHEA, whether endogenously secreted or exogenously administered.¹ As dietary supplements, these products do not require evaluation for safety and efficacy by the US Food and Drug Administration (FDA). These products do not have to be manufactured in compliance with the FDA's current Good Manufacturing Practices, nor do they have to meet quality control standards expected of approved drugs.^{2 - 3}

To assess the accuracy of the manufacturers' label claims, we analyzed DHEA products available to the public at health food stores in the United States for the presence and total content of DHEA. Three randomly chosen dosage forms from each of the products were analyzed for DHEA content using high-performance liquid chromatography. Ultraviolet photo diode array and Fourier transform infrared spectroscopy were also performed for definitive identification of DHEA in the products. Results are summarized in Figure 1. Only 7 of 16 products were found to have DHEA content within the typical pharmaceutical product specifications of 90% to 110% of labeled claim. Of the remaining products, no DHEA was detected in 1 product, and trace amounts of DHEA were detected in 2 other products (0.6 mg, coefficient of variation [CV] 78%, and 0.5 mg, CV 80%, respectively). The latter 2 products were labeled as containing "naturally occurring DHEA" with no specific amount indicated on the label. One product was found to contain an average of 150% of the labeled amount, CV 32%.

Although DHEA is widely available for self-administration as a dietary supplement, the metabolic effects of exogenously administered DHEA in children, men, and premenopausal women are largely unknown. Long-term administration of DHEA has been observed to increase male and female sex hormones significantly, suggesting possible risks to hormonally dependent tissues, including endometrium, breast, and prostate gland.^{1 ,4 - 5} Long-term DHEA administration may also cause insulin resistance and hypertension and reduce high-density lipoprotein cholesterol.⁶

The variability of content (range, 0%-150%) observed should raise concerns about the availability of this potent drug or hormone, which is not required to be manufactured in compliance with Good Manufacturing Practices and is ingested without medical supervision. Only half of products tested met the manufacturers' label claims. In the worst cases, the product contained no DHEA or, as in 1 case, contained 150% of the amount claimed on the label. This wide range of variation of actual DHEA content compared with label claims has important safety implications for this steroid, which is endogenously converted to potent androgenic and estrogenic sex steroids.^{5 - 6}