Hypothyroidism — an underactive thyroid — affects roughly 5% of adults worldwide, with women diagnosed five to ten times more often than men. The thyroid sits in the front of the neck and produces two hormones: thyroxine (T4) en triiodothyronine (T3), which together set the metabolic rate of every cell in the body. When the gland fails — most commonly through autoimmune destruction (Hashimoto’s thyroiditis), surgery for nodules or cancer, radioiodine ablation, congenital absence, or severe iodine deficiency — symptoms emerge gradually: fatigue, weight gain, cold intolerance, constipation, dry skin, hair shedding, depression and brain fog. Untreated hypothyroidism in pregnancy raises the risk of miscarriage and impairs fetal neurodevelopment. The diagnosis is biochemical: a raised thyroid-stimulating hormone (TSH) with a low or low-normal free T4.
Treatment is hormone replacement. The first-line drug is levothyroxine — synthetic T4 — taken once daily on an empty stomach. Levothyroxine has a long half-life (~7 days) which produces smooth blood levels with simple once-daily dosing. The body converts T4 to the more active T3 in peripheral tissues exactly as it does with the natural hormone, which is why most patients feel completely well on T4 alone. Dose is titrated against TSH every 6–8 weeks until the level sits in the target range (usually 0.5–2.5 mIU/L), then monitored annually.
Levothyroxine (T4) brands stocked at MedsBase
All four brands below contain the identical active ingredient — levothyroxine sodium. They differ in manufacturer, excipients and price point. Once your TSH is stable on one brand, sticking with it avoids the small bioequivalence variations that can shift TSH outside target.
Eltroxin — GlaxoSmithKline (GSK), 100 mcg tablet. Globally recognised brand used since the 1960s; the same molecule as Synthroid and Levoxyl.
Thyronorm — Abbott India, full 25/50/100/125/150 mcg titration range. The most widely prescribed levothyroxine in India.
Thyrox — Macleods Pharmaceuticals, 25/100/125/200 mcg. Includes the higher 200 mcg strength useful for post-thyroidectomy TSH suppression.
L-Thyroid — budget option, full 25 to 150 mcg titration range.
Liothyronine (T3) — second-line
Liothyronine 25 mcg is synthetic T3 — about four times more potent than levothyroxine, with a much shorter half-life (~24 hours). Liothyronine bypasses the T4-to-T3 conversion step entirely. Its place in therapy is narrow:
A small added dose alongside levothyroxine in selected patients with persistent hypothyroid symptoms despite a normal TSH on T4 monotherapy — usually a specialist endocrinology decision after other causes are excluded.
Short-term preparation for thyroid cancer scans (allows quicker TSH rise after stopping).
Myxoedema coma in hospital, given intravenously alongside T4.
Off-label augmentation in treatment-resistant depression.
Liothyronine is niet a wholesale replacement for levothyroxine and is not a weight-loss drug — misuse in euthyroid people causes atrial fibrillation, bone loss and muscle wasting. The Cochrane systematic review found no consistent benefit of T4+T3 over T4 monotherapy for routine quality-of-life improvement.
Thyroid nutritional support — not a treatment substitute
Thyropace is an L-Tyrosine + Iodine capsule supplement. It is included in this category because it supports thyroid function nutritionally, but it is niet a substitute for levothyroxine in diagnosed hypothyroidism. Thyropace can be appropriate for confirmed mild iodine deficiency or as adjunct nutritional support during pregnancy. It should be avoided in autoimmune Hashimoto’s thyroiditis, Graves’ disease, and before radioiodine scanning — excess iodine flares autoimmunity and complicates radio-tracer imaging.
Critical absorption rules for any T4 or T3 product
Levothyroxine and liothyronine absorption are dramatically reduced by food, coffee, soy and several common medications. The rules below are essential, not optional:
Take on an empty stomach, first thing in the morning, with plain water.
Wait 30–60 minuten before any food, coffee or other tablet.
Separate from calcium, iron, magnesium, zinc, aluminium supplements / antacids by at least 4 hours.
Separate from proton pump inhibitors (omeprazole, esomeprazole, pantoprazole) — gastric acid is needed for full absorption.
Separate from cholestyramine, sevelamer, orlistat by at least 4 hours.
Pregnancy: levothyroxine requirement rises 25–50% by mid-pregnancy — recheck TSH every 4 weeks in the first half of pregnancy.
Older adults / cardiac patients: start low (25–50 mcg) and titrate slowly to avoid triggering ischaemia or atrial fibrillation.
Every product in this category is dispatched from a WHO-GMP gecertificeerde fabrikant, FDA-approved generic where applicable, with discreet packaging and worldwide shipping. Each product page includes a TSH-titration table, full drug-interaction list, side-effect profile by over- vs under-treatment, and a hand-picked sibling alternatives panel.