How is synthroid (levothhyroxine) made? Where does it come from?

Here in Canada, the only 'natural' thyroid hormone available is desiccated - 'dried out' - pig thyroid gland. Using any animal product creates the risk of an immune reaction: our bodies recognize 'foreign' substances and try to destroy them. This essentially adds another medical problem. Personally, I'd avoid desiccated porcine glandular hormone. More commonly, those who require a better balance of T3 to T4 will resort to a compounded product but only specialized, well-equipped pharmacies are capable of producing compounded drugs. Your endo or family doc would have to consult with the compounding pharmacist and exchange info on Synthroid dose currently used and thyroid function test results after which a calculation is made of the specific T4/T3 doses in the compounded product you will receive. Obviously, the cost per unit dose will be much higher than the cost of Synthroid. For example, depending on the amounts of each component, T3 being the more costly of the two, a dose/capsule would run between CDN $1.30 and $1.50 each. Right now, 100 Synthroid 200 mcg runs about $18.00 and some other doses are about $30.00 per hundred. Any pharmacist can direct you to such specialized services. The compounded thyroid hormone is a mixture of T4 (levothyroxine, as in Synthroid) and T3 (liothyronine, as in Cytomel) so obviously, a better balance of measured levels should result. This is especially effective when T4 levels are high-normal and T3 values are low-normal, suggesting a possible issue concerning the deiodinase enzyme responsible for T4 to T3 conversion. Stressed people usually have high cortisol levels and that can suppress deiodinase activity. Zinc and selenium supplementation can often improve T3/T4 balance and recommended doses would be Zn - 50 mg/day and Se - 400 mcg/day. As to Synthroid production... the processes are obviously covered by patents and if you're really curious, you could do a patent search, buy a copy and study it. However, unless you're an organic chemist who specializes in synthesis, what you read will be just gibberish. I suggest you visit the Abbott website and check what's called the 'Product Monograph' which runs to 36 pages. On page 28, you'll find both the chemical and structural formulas, the full chemical names and other data like molecular weight. If you struggle with the product monograph, scrap any thought of studying the patent.

If you want my 'bottom line' advice, I'd suggest you stick with Synthroid IF your thyroid profile is normal AND you are essentially symptom-free, i.e., you feel 'normal'. Certainly adding both Zn and Se won't hurt and might even help. The latter is a very potent antioxidant which reportedly helps reduce arterial plaque formation resulting from high cholesterol. Zn is said to help with male sexual function and may delay prostate enlargement.