Methimazole (also known as Tapazole or Thiamazole or MMI) is an antithyroid drug. Methimazole binds to thyroid peroxidase and thereby inhibits the conversion of iodide to iodine. Thyroid peroxidase normally converts iodide to iodine (via hydrogen peroxide as a cofactor) and also catalyzes the incorporation of the resulting iodide molecule onto both the 3 and/or 5 positions of the phenol rings of tyrosines found in thyroglobulin. Thyroglobulin is degraded to produce thyroxine (T4) and tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. So methimazole effectively inhibits the production of new thyroid hormones. Methimazole is used for the treatment of hyperthyroidism, goiter, Graves disease and psoriasis.

Propylthiouracil is thyroid peroxidase inhibitor used to treat hyperthyroidism, which includes hyperthyroidism due to Graves' disease and toxic multinodular goiter. Propylthiouracil is used to ameliorate symptoms of hyperthyroidism in preparation for thyroidectomy or radioactive iodine therapy in patients who are intolerant of methimazole.

Resorcinol is a benzenediol. Resorcinol is commonly used in hair dyes and acne medication. Resorcinol works by breaking down rough, scaly, or hardened skin. Resorcinol also disinfects the skin to help fight infection. Resorcinol topical (for the skin) is used to treat pain and itching caused by minor cuts and scrapes, burns, insect bites, poison ivy, sunburn, or other skin irritations. Resorcinol topical is also used to treat acne, eczema, psoriasis, seborrhea, corns, calluses, warts, and other skin disorders. Resorcinol is included in the FDA final rule list of all permitted active ingredients for OTC topical acne products. Permitted combination active ingredient product - Resorcinol in 2 percent concentration in combination with sulfur in concentrations of between 3 and 8 percent. In oxidative hair dyes, resorcinol is regulated to 5% or below in practice, however, many manufacturers limit the level of free resorcinol in oxidative hair dyes to 1.25%. Resorcinol is limited to 0.5% in shampoos and hair lotions. Resorcinol is usually present in anti-acne preparations at a maximum concentration of 2%. The concentration of resorcinol can be much higher in peels, in some cases around 50%. Jessner’s solution (resorcinol in ethyl alcohol, 14% w/v; lactic acid, 14%; and salicylic acid, 14%) is commonly used in chemical peeling. A specialized medical use of resorcinol is in biological glues (gelatin–resorcinol–formaldehyde glue) for cardiovascular surgery, in particular aortic operations.

Sodium 2-Mercaptobenzothiazole (sodium MBT) is utilized as a corrosion inhibitor and fungicide. By analogy to MBT, sodium MBT is identified as a skin sensitizer. Sodium 2-Mercaptobenzothiazole is also used to make rubber accelerators, as a preservative for latex paint and wood, a metal chelator, and a thermal stabilizer (methyl methacrylate copolymers, acrylonitrile polymers, polyester fibers, anion exchange resins, polyoxyphenylene, and silicon fluids), also used in electroplating (silver, nickel, and cobalt), to separate sulfide ore from copper ore, for dyeing textiles, in transmission fluids, and to prevent discoloration of freeze dried bananas; uses of 50% aqueous solution include as a corrosion inhibitor for nonferrous metals in antifreeze and coolants and in paper mill systems; used as a biocide in metalworking fluids and paper manufacturing.

Thiouracil or 2-thiouracil was introduced in 1943 as the first thionamide anti-thyroid drug. Owing to a high frequency of adverse reactions, especially agranulocytosis, use of thiouracil was abandoned in favor of other, less toxic drugs. Thiouracil is not currently used as a thyrostatic drug in humans. Thiouracil inhibits thyroid activity by blocking the enzyme thyroid peroxidase. It is also it is a highly selective inhibitor of neuronal nitric oxide synthase, by interfering with the substrate- and tetrahydrobiopterin (BH(4))-binding to the enzyme. Due to its ability selectively accumulating in de novo-synthesized melanin in overactive melanin-producing cells and thus providing a means to localize melanoma cells, thiouracil can represent a useful new tool to identify modulators of human hair pigmentation.

Diiodotyrosine (DIT) is a regulatory ligand for thyroid peroxidase, enzyme, which is involved in the production of thyroxine (T4) and triiodothyronine (T3), the thyroid hormones. Diiodotyrosine was proposed to be a new marker of leukocyte phagocytic activity in sepsis and severe infections.

Carbimazole is a prodrug for methimazole used to treat hyperthyroidism and thyrotoxicosis during pregnancy and breast breastfeeding. Carbimazole is rapidly metabolized to methimazole, which is responsible for the antithyroid activity. Carbimazole is an antithyroid agent that decreases the uptake and concentration of inorganic iodine by the thyroid, it also reduces the formation of di-iodotyrosine and thyroxine. Once converted to its active form of methimazole, it prevents the thyroid peroxidase enzyme from coupling and iodinating the tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4. Doses of carbimazole of 30 mg daily or 50 mg weekly have not adversely affected the few breastfed infants studied and no cases of thyroid function alteration have been reported among infants exposed to methimazole via breastmilk. Carbimazole is not approved for marketing in the United States by the U.S. Food and Drug Administration but is available in other countries.

Resorcinol is a benzenediol. Resorcinol is commonly used in hair dyes and acne medication. Resorcinol works by breaking down rough, scaly, or hardened skin. Resorcinol also disinfects the skin to help fight infection. Resorcinol topical (for the skin) is used to treat pain and itching caused by minor cuts and scrapes, burns, insect bites, poison ivy, sunburn, or other skin irritations. Resorcinol topical is also used to treat acne, eczema, psoriasis, seborrhea, corns, calluses, warts, and other skin disorders. Resorcinol is included in the FDA final rule list of all permitted active ingredients for OTC topical acne products. Permitted combination active ingredient product - Resorcinol in 2 percent concentration in combination with sulfur in concentrations of between 3 and 8 percent. In oxidative hair dyes, resorcinol is regulated to 5% or below in practice, however, many manufacturers limit the level of free resorcinol in oxidative hair dyes to 1.25%. Resorcinol is limited to 0.5% in shampoos and hair lotions. Resorcinol is usually present in anti-acne preparations at a maximum concentration of 2%. The concentration of resorcinol can be much higher in peels, in some cases around 50%. Jessner’s solution (resorcinol in ethyl alcohol, 14% w/v; lactic acid, 14%; and salicylic acid, 14%) is commonly used in chemical peeling. A specialized medical use of resorcinol is in biological glues (gelatin–resorcinol–formaldehyde glue) for cardiovascular surgery, in particular aortic operations.

Sodium 2-Mercaptobenzothiazole (sodium MBT) is utilized as a corrosion inhibitor and fungicide. By analogy to MBT, sodium MBT is identified as a skin sensitizer. Sodium 2-Mercaptobenzothiazole is also used to make rubber accelerators, as a preservative for latex paint and wood, a metal chelator, and a thermal stabilizer (methyl methacrylate copolymers, acrylonitrile polymers, polyester fibers, anion exchange resins, polyoxyphenylene, and silicon fluids), also used in electroplating (silver, nickel, and cobalt), to separate sulfide ore from copper ore, for dyeing textiles, in transmission fluids, and to prevent discoloration of freeze dried bananas; uses of 50% aqueous solution include as a corrosion inhibitor for nonferrous metals in antifreeze and coolants and in paper mill systems; used as a biocide in metalworking fluids and paper manufacturing.

Sodium 2-Mercaptobenzothiazole (sodium MBT) is utilized as a corrosion inhibitor and fungicide. By analogy to MBT, sodium MBT is identified as a skin sensitizer. Sodium 2-Mercaptobenzothiazole is also used to make rubber accelerators, as a preservative for latex paint and wood, a metal chelator, and a thermal stabilizer (methyl methacrylate copolymers, acrylonitrile polymers, polyester fibers, anion exchange resins, polyoxyphenylene, and silicon fluids), also used in electroplating (silver, nickel, and cobalt), to separate sulfide ore from copper ore, for dyeing textiles, in transmission fluids, and to prevent discoloration of freeze dried bananas; uses of 50% aqueous solution include as a corrosion inhibitor for nonferrous metals in antifreeze and coolants and in paper mill systems; used as a biocide in metalworking fluids and paper manufacturing.