What testosterone level is low enough to need treatment?

Short answer: There’s no single universal cutoff — treatment is usually considered when a man has consistent symptoms of testosterone deficiency AND morning total testosterone that is repeatedly low. In practice most U.S. guidelines use about 300 ng/dL (10.4 nmol/L) as the working threshold; the Endocrine Society guideline uses 264 ng/dL (9.2 nmol/L).

Key points to know

• You need both symptoms (low libido, erectile dysfunction, fatigue, loss of muscle mass, depressed mood, decreased bone density, etc.) and biochemical confirmation before starting therapy.
• Measure total testosterone in the morning (ideally 7–10 AM), fasting, on at least two separate days when you are well.
• If total testosterone is borderline or SHBG is abnormal, a calculated free testosterone or measured free testosterone can help; labs use different reference ranges.
• If low, your clinician will usually check LH/FSH (to distinguish primary vs secondary hypogonadism), prolactin, and basic safety labs (CBC, PSA, liver function) before and during treatment. Baseline bone density may be considered in some men.

Common numeric guidance (for adults)

• Total testosterone <300 ng/dL (10.4 nmol/L) — commonly used cutpoint to evaluate for possible treatment.
• Endocrine Society: <264 ng/dL (9.2 nmol/L) as the threshold for biochemical low T in their guideline.
• If total testosterone is “borderline,” use calculated free testosterone or repeat testing.

Safety and contraindications

• Do not start testosterone therapy if you have untreated prostate or breast cancer. High PSA, hematocrit >50%, or certain heart disease concerns require careful evaluation.
• Fertility: exogenous testosterone can suppress sperm production — discuss alternatives if you want children.

Practical next steps and services

• Get tested through reputable labs such as Quest Diagnostics or LabCorp (widely available, fast results).
• See your primary care physician first; if abnormal or complex, ask for referral to an endocrinologist or urologist. Good specialty centers with reliable information and care include Mayo Clinic and Cleveland Clinic.
• If you prefer telemedicine options for evaluation and treatment, services such as Hims or Roman offer remote assessment and prescription for testosterone therapy; be sure they follow guideline-based testing and safety monitoring and consider getting an in-person specialist opinion for complicated cases.

If you want, tell me your age, symptoms, and any prior lab results (total testosterone, time of day, date) and I can help interpret them and suggest next steps.