Thyroid Stimulating Hormone

also known as TSH

NORMAL_RANGE
0.4 – 4 mIU/L
UNIT
mIU/L

/WHAT_IT_IS

TSH is the pituitary signal that drives thyroid hormone production. It's the most sensitive screen for thyroid dysfunction and worth checking annually on TRT.

/NORMAL_RANGE

Reference: 0.4–4.0 mIU/L. Optimal: 1.0–2.0 for most adults.

What does high TSH mean?

  • +Hypothyroidism (Hashimoto's, iodine deficiency, postpartum thyroiditis).
  • +Some medications (lithium, amiodarone).

What does low TSH mean?

  • +Hyperthyroidism (Graves', toxic nodule).
  • +Excess thyroid hormone supplementation.

/ON_TRT

Untreated hypothyroidism mimics low T (fatigue, low libido, weight gain) and raises SHBG, suppressing free T. Hypothyroidism is the most commonly missed reason men on TRT don't feel right despite "perfect" labs. If TSH is >2.5 with symptoms, check free T3 and free T4 and antibodies.

/RELATED

FAQ

/01Can TRT cause thyroid problems?+

TRT doesn't directly cause thyroid disease, but autoimmune thyroid conditions cluster with other endocrine issues. Worth annual screening even if asymptomatic.

/TRACK_THIS

Track TSH in the app.

Upload your lab PDF — MyTRT extracts every marker with Gemini Vision. Charts, trends, and TRT-aware insights. Free on iOS and Android.

Last reviewed: 2026-06-04 · MyTRT does not provide medical advice. Always consult your physician.