Deb asked
Is Levoxyl the same as thing as Synthroid?
Answer
Both Synthroid and Levoxyl contain the same active ingredient, levothyroxine, so they are the "same" in that regard.
They do however, contain different inactive ingredients so they are not identical. Below, we have listed the ingredients for the 100 microgram (mcg) strength of each drug:
Synthroid 100 mcg Ingredients:
- Acacia Senegal
- Confectioners sugar
- Corn Starch
- D&C Yellow No. 10
- FD&C Yellow No. 6
- Lactose
- Magnesium Stearate
- Povidone
- Talc
Levoxyl 100 mcg Ingredients:
- Croscarmellose Sodium
- D&C Yellow No. 10
- FD&C Yellow No. 6
- Magnesium Stearate
- Microcrystalline Cellulose
Generic levothyroxine can legally be substituted for both Synthroid and Levoxyl as the FDA has classified it as 'bioequivalent' to the brand name products.
There was considerable controversy in the late 1990's regarding drugs containing levothyroxine. Levothyroxine had been available on the market prior to 1962, which allowed it to bypass the new FDA drug application process, essentially being 'grandfathered' in as a drug.
After the FDA starting receiving a multitude of reports regarding dosage inconsistency, they required all manufacturers of levothyroxine products to submit new drug applications. This eventually standardized the levothyroxine market, ensuring all products had consistent potency and bioavailability.
