by Dr. Susan R.Meyer

I have been taking Synthroid for eighteen years now for an overactive thyroid to maintain thyroxine levels. Periodically, the dosage has been reduced over the years, so I wasn’t surprised that in August it was reduced. I was surprised, though, to have been prescribed a generic form of the drug. I recalled that my original endocrinologist had warned against the generic but felt that so much had changed in eighteen years that I could ignore the warning.

Over the next two months, I discovered that his warning was still something I shouldn’t have ignored. At first, I was feeling tired and mildly depressed. I ignored it. About a month in, I started to experience brain fog. I couldn’t remember things. I was making odd mistakes, like sending out an email headed “Tuesday meeting” for something clearly happening on Wednesday. I started thinking about getting tested for dementia. I kept getting more tired. I would sit down on the couch and promptly fall asleep. I had more brain fog. My joints and muscles were aching. I fell asleep at the theater. I gained seven pounds in a week. Clearly, something was wrong.

I suspected that the generic drug was not working and asked my endocrinologist for a prescription for the branded drug. Three weeks in, all the symptoms – and the weight – are almost gone. My pharmacist mentioned that generic version for Synthroid, especially at the micro-dose level, doesn’t work properly. Since I take other generic drugs with no problem, I was curious and did a little research before sharing my cautionary tale. Here’s what I found:

In order to get a stamp of approval from the FDA, a generic medication must be “bioequivalent” to its brand-name counterpart. This means that chemically the two must be pretty much the same, although makers are allowed 20% variation in the active ingredient from that original formula. At .75 micrograms, it seems to me that this could have a significant impact. I also found that generics may have different inactive ingredients (binders, etc.) that may affect the absorption of the active ingredient. In recent years, some generics have been imported from countries where the manufacturing process may not be closely monitored.

A study in the National Library of Medicine warned against switching among forms of the drug and stated that “Continuous use of Synthroid® was associated with a significantly higher likelihood of maintaining the TSH laboratory value within a guideline recommended range and a significantly lower likelihood of being diagnosed with adverse clinical outcomes. Switching to an alternative LT4 formulation was associated with a higher likelihood of a TSH laboratory value outside of the target range in the post-period as compared to continuous use of Synthroid®. Compared to continuous treatment, switching was associated with higher likelihoods of being diagnosed with a number of negative clinical outcomes: chronic kidney disease, depression, fatigue, hypertension, or obesity.”

What generic drugs are you taking? Check periodically that you are getting the desired results, as distributors often switch providers. Have regular blood work. Inform your doctor of any changes you are experiencing. I’ve been hearing of others who have experienced difficulties with other medications. Don’t let this be you!

Dr. Susan R. Meyer knows how to help people create the life they want and has spent decades working with women and men who want to create a clear path to success. Whether you’re looking for a totally different path or simply want to tweak your career trajectory, her extensive experience in life, career, and transition coaching will help you take an informed look at your own life and build on what’s revealed. She is the author of two books, “I’m Susan and I’m a Serial Careerist,” and, Fifty Over Fifty: Wise and Wild Women Creating Wonderful Lives (And You Can Too!).  Learn more at www.susanrmeyer.com