Erectile dysfunction

Fasting laboratory tests

• Fasting plasma glucose
• Lipid profile
• Total serum testosterone (in the morning, between 7 am and 11 am; if signs of androgen deficiency)if neededTo be requested for signs suggestive of androgen deficiency (reduced sexual desire, fewer morning erections), the only case in which the 2017 French recommendation for the non-sexologist doctor adds androgen tests ^[2]; the Canadian recommendation adds failure of phosphodiesterase type 5 inhibitors ^[3]. The EAU (European Association of Urology) proposes it for all patients, in the morning and fasting ^[1]: the doctor following the EAU can therefore prescribe it from the outset. Sample between 7 am and 11 am ^[4], 10 am being the cut-off time for the 2026 edition ^[5].
• HbA1c (in place of fasting plasma glucose)if neededThe EAU writes “fasting plasma glucose or HbA1c” ^[1]. HbA1c is reimbursed only in monitoring glycaemic control in known diabetes ^[6].
• Total PSA (if signs of prostate disease)if needednon-French guidelineThe EAU lists total PSA among the tests to consider in some patients, in the presence of warning signs ^[1]. PSA measurement is not a routine test for erectile dysfunction; for a screening request, see the page “PSA: request for prostate cancer screening and raised PSA”.
• Serum prolactin (reduced sexual desire, low testosterone)if needednon-French guidelineThe EAU lists prolactin among the tests to consider in some patients, in the presence of warning signs ^[1]; it is to be considered in reduced desire with low testosterone ^[4,5].
• LH (low total testosterone)if needednon-French guidelineThe EAU lists LH among the tests to consider in some patients ^[1], and to be considered when the pathophysiology of the testosterone deficiency needs to be explored ^[4].
• SHBG (to calculate free testosterone)if needednon-French guidelineMeasurement of bioavailable or calculated free testosterone may sometimes be needed to corroborate total testosterone ^[1]. See the page “Testosterone deficiency in men”.
• TSH (if signs or symptoms of hypothyroidism)if needednon-French guidelineThyroid disorders are among the endocrine causes of erectile dysfunction; an American Family Physician review (2016) recommends TSH in men with signs or symptoms of hypothyroidism ^[7]. The 2017 French recommendation advises general laboratory tests, supplemented by androgen tests if there are signs of deficiency ^[2].