Dear Dr. Vliet,

My doctor prescribed Femring to give me estradiol in what is supposed to be stable delivery over 3 months, but I can tell that it wears off after about ONE month, not three, and the vaginal dryness and other menopausal symptoms I’ve had – hot flashes, waking up a lot at night feeling hot and my heart racing, fuzzy thinking, and low energy – all start coming back. My doctor says that’s not possible, it is “supposed” to last 3 months! Am I crazy? Or have you seen Femring wear off sooner than the advertising says? I am in my 50s and I need to function for work and my family.

Yes, this is a common problem I have seen since Femring first became available in the US several years ago.  Over the years of treating many patients with Femring, it was clear that the Femring dropped drastically in estradiol delivery after only one month, not the 90 days the manufacturer advertises. When the Femring wears off prematurely, most patients have abrupt return of disruptive menopausal climacteric symptoms that affect quality of life and function, just as you describe and more! I have been able to document a corresponding drop in serum estradiol level concurrent with the return of the above symptoms. Since nothing else changed to cause this, there is clearly less effective delivery from Femring happening to cause this problem on a consistent basis.

This shorter-than-advertised drop in estradiol delivery with Femring has occurred in numerous patients over the years I have used this product for women. I recently was informed by an attorney and patient that she had actually researched the data the company presented to the FDA in the approval application, and found that the company itself had submitted data to the FDA showing that they knew that Femring did not last 90 days (as marketed). You may find these documents here, on the FDA website:

If you review these documents on the patent information itself, you will see the patent is for a drug delivery device that will deliver the medicine at a substantially constant rate for 3 WEEKS.  NOT 3 MONTHS.  3 WEEKS. Yet the company still marketed the product for 90 days of stable delivery, and the FDA has allowed this. 

So now patients and physicians are in a catch-22: the patient needs stable delivery the product was known NOT to provide, yet because the company and the FDA are claiming that it is effective for 90 days, patients are penalized and denied coverage by insurance companies if they need to change the Femring in less than 90 days.

Penalizing the patient is even more egregious now that I know the company and FDA actually had the data to show the Femring estradiol level dropped off significantly at 3 weeks. So in fact, the observations from my patients and my own clinical verification of actual estradiol blood levels confirms exactly what the company reported to the FDA at the beginning of their application for approval, but apparently  was never disclosed to physicians, patients, and insurance carriers. 

In all the patients I have treated with Femring since it became available, every single one of them has needed to change it more frequently than every 90 days to maintain symptom control and therapeutic benefit. None of my patients have had adverse effects (symptoms or blood levels) of excess estradiol from changing Femring every 4-6 weeks based on their needs. In fact, quite the contrary: their symptoms have been better controlled and estradiol levels remained in the target range for benefits. Based on the information on file at the FDA from the company, it is not surprising that you need monthly replacement, and my opinion is that Femring should be covered as medically necessary treatment to control your symptoms and provide the benefit of estradiol for your quality of life and health.