allergy to polyethylene glycol, propylene glycol, ethylene & butylene glycols

The NDC: Your New Best Friend

It’s the ONLY Sure Thing

How to Find & Use the NDC to Stay Safe

Those of us who have been successfully living without glycols for years are big fans of the NDC number. If you’ve ever wondered how to keep yourself away from glycols when the ingredients aren’t on the label, get to know the NDC.

Every drug on the market has a unique identification number that ties it to the manufacturer and their specific formula. It’s called the National Drug Code or NDC number, and it can help you find out exactly what is in that drug – even ‘hidden’ glycols. It’s assigned by the US government and it’s the way that particular drug is identified, registered and allowed to be prescribed and sold. Because it’s a number, there’s no confusion with spelling or similar names, and companies are free to change the trade name of the product but the NDC must be unique to that product, no matter what it’s called on the shelf.

Non-prescription over-the-counter (OTC) products and medications also have NDCs,


Decoding the NDC#

The NDC is divided into three sections, either with spaces or dashes between them, and if you don’t get those spaces or dashes right, you’ll be looking at the wrong information.

The first part of the NDC, usually four or five digits, indicates the manufacturer.
The NDC is different for each manufacturer a company may have multiple NDCs. Sometimes there are zeroes at the beginning or end of the number, and those are important. Sun Pharmaceuticals, for example, uses 10631 and 47335, so if you see an NDC where the first five numbers are 10631, you know right away it’s made by Sun.

The second part of the NDC indicates the dosage and the form, and the third part indicates the size of the bottle it came in. The third part is the least important.

Here’s an example:
Every tablet of 25 mcg levothyroxine sodium by Lannet has an NDC of 00527-1341, with an additional two digits at the end indicating the number of tabs in the package. So the 100 count bottle is 00527-1341-01, and the 1000 count bottle is 00527-1341-10.

The 50 mcg tablets of levothyroxine sodium by Lannet has an NDC of 00527-1342-01 for the 100 count bottle. (The size of bottle refers only to the size as it comes to the pharmacy when they order and has nothing to do with the size of your prescription).

also makes levothyroxine, 25 mcg, with an NDC of 0378-1800-77 for the 90 tab bottle.

Each one can have different ingredients, as long as the active ingredient is the same. Different strengths of the same medication can have different inactive ingredients, and those inactives can change without notice.

Now that you know how to read an NDC, how do you use it? Hop on over to Managing Prescriptions with a Glycol Allergy for more info.