Neo-Mercazole is a brand of carbimazole, a tablet for an overactive thyroid. Start here for what it is, doses, side effects, alternatives, common questions and where to buy.
Independent guide
Neo-Mercazole is a brand name for carbimazole, a prescription tablet that lowers thyroid hormone production when the thyroid is overactive (hyperthyroidism). In the body it turns into methimazole, which does the work.
We are not the company that makes or licenses Neo-Mercazole. Each page draws on product information, regulators and published studies, and lists its sources. It is general information, not medical advice.
Uses, other names, how long it takes, who should not take it.
Starting and maintenance doses, missed doses, stopping.
Common effects and the rare serious ones.
Birth defect risk, switching to PTU, feeding.
Thyroid checks, blood counts and TRAb.
Pharmacies that list carbimazole and methimazole.
Carbimazole (Neo-Mercazole) and methimazole compared, with a dose conversion table, which countries use which, and what to do when you move abroad or your pharmacy only stocks the other one.
What an overactive thyroid is, the main causes (Graves' disease, toxic nodules, thyroiditis), symptoms, the blood tests that diagnose it, and how antithyroid tablets, radioiodine and surgery fit together.
How hyperthyroidism shows up in older cats, how vets confirm it, and how methimazole, carbimazole (Vidalta), radioiodine, surgery and iodine-restricted food compare.
Graves' disease is the commonest cause of an overactive thyroid. What triggers it, how it is diagnosed, how antithyroid tablets such as Neo-Mercazole, radioiodine and surgery compare, and what predicts remission.
An overactive thyroid. The product information lists Graves’ disease and toxic nodular goitre, a 12 to 18 month course aimed at lasting remission, bringing levels to normal before thyroid surgery, and use before and after radioactive iodine. More in what Neo-Mercazole is.
Yes. Neo-Mercazole is a brand name and carbimazole is the medicine inside it, so “the generic name” and “the other name” are both carbimazole. Plain carbimazole tablets from other makers work the same way.
Closely related, not identical. Your body turns carbimazole into methimazole (thiamazole), which does the work. The milligram doses differ: roughly 10 mg of carbimazole matches 6 mg of methimazole, so switching is a job for your doctor. See the dose conversion table.
The New Zealand data sheet describes a 5 mg pale pink tablet marked “Neo 5”. In India, Abbott sells Neo Mercazole 5 mg and 10 mg. In the UK, carbimazole comes as 5, 10, 15 and 20 mg tablets, mostly under the generic name.
The tablets stop new hormone being made but leave the hormone already stored in the thyroid, so it takes time. The NHS says many people feel better within one to three weeks and get the full effect in one to two months. Your first blood test usually comes at four to six weeks.
Either way with food: the NHS says you can take carbimazole with or without a meal. Alcohol does not change how it works, but avoid it if the tablets make you dizzy.
Take it as soon as you remember. If your next dose is already due, the NHS says to take both together. If you are unsure, ask your pharmacist. More on dosage.
For Graves’ disease the usual course is 12 to 18 months for adults, adjusted by blood tests. Some people take a low dose for years instead of having radioactive iodine or surgery. Do not stop just because you feel better.
Carbimazole is linked with birth defects, mostly from use in the first trimester, so use reliable contraception and talk to your doctor before trying for a baby; most specialists switch to PTU for the early weeks. Only small amounts reach breast milk, and the NHS says breastfeeding is usually fine. See pregnancy and breastfeeding.
Yes. Neo-Mercazole, carbimazole and methimazole are prescription medicines, and treatment should start only after blood tests confirm an overactive thyroid. Keep up the blood tests while you take it.
Generic carbimazole is listed by PockDose in Hong Kong, Yasabai in Thailand and VGR Australia. Pharmacies in other countries are on where to buy.
