SAT-168 Beware of the hidden ingredients and supplement use in your patients with elevated testosterone

Abstract Disclosure: M. Pattipati: None. M. Chang Villacreses: None. Background: Natural supplements and energy drink use is quite common in the United States and there is an increase in the trends compared to past years. Clinical Case26-year-old man with a history of Chiari malformation presented to endocrine clinic for hypoglycemia evaluation. A continuous glucose monitor was placed which revealed occasional fasting and post prandial symptomatic hypoglycemia ranging between 54 to 68 mg/dl. Laboratory showed a total testosterone of 995 ng/dl (264-916 ng/dl), free testosterone 205 pg/ml (52-280 pg/ml), SHBG 32 nmol/L (16.5-55.9 nmol/L), LH 2.5 mIU/ml (1.5-9.3 mIU/ml), FSH 2.6 mIU/ml (1.4-18.1 mIU/ml), DHEA-S 330 mcg/dl (74-617 mcg/dl), Serum Estradiol 62 pg/ml (<29 pg/ml), HCG < 1 IU/L (0-3 IU/L), Cortisol 6.1 mcg/dl (6.7-22.6 mcg/dl), ACTH 27.4 pg/ml(7.2-63.3 pg/ml), TSH 2.60 mIU/L (0.40-4.50 mIU/L), Vitamin D 25 OH 17 ng/ml (30-100 ng/ml), Vitamin D 1,25 OH 56 pg/ml (18-72 pg/ml), Calcium 10.7 mg/dl (8.6-10.3 mg/dl), HbA1c 5.2% (<5.7%), normal IGF-1 and IGF-2 and work up was negative for insulin antibodies. A cosyntropin stimulation test ruled out adrenal insufficiency. Extensive Oncology evaluation revealed no biochemical evidence of tumors. A mixed meal study was performed which revealed reactive hypoglycemia with the lowest blood glucose during the study being 63 mg/dl and C peptide of 4.9 ng/ml (0.5-3.3 ng/ml). After a deep review of habits and food intake, the patient was recommended to discontinue all supplement and energy drinks. Repeat labs three months later showed normalization of testosterone, calcium, and resolution of hypoglycemia with a total testosterone of 438 ng/dl (264-916 ng/dl), free testosterone 66 pg/ml (52-280 pg/ml), SHBG 45.4 nmol/L (16.5-55.9 nmol/L), calcium 10.1 mg/dl (8.6-10.3 mg/dl and a glucose of 105 mg/dl. Discussion: Guarana is a native fruit of Amazonian basin which has been used as a traditional medicine for centuries by indigenous populations. It is used as a stimulant due to high caffeine content and used as an ingredient in energy drinks to boost sexual function in Brazil. Our case is about a patient unknowingly taking Guarana, a hidden ingredient found on the food label of Nutritional supplement Zip fizz, resulting in elevated testosterone levels, hypoglycemia, and hypercalcemia. Conclusion: Testosterone replacement has been shown to impact insulin sensitivity and calcium levels. Our patient had borderline hypoglycemia secondary to increased testosterone that resolved after supplement cessation. Careful clinical history and thorough review of ingredients in food labels is essential to identify potential confounders of elevated testosterone levels. Presentation: Saturday, July 12, 2025