Water Retention from Minoxidil

Dr. Rassman,

Hello.

Question for you. I wrote you before, and so have others, about puffy or “swollen” faces from minoxidil use. You said if this happens it would be due to an allergic reaction. I was reading the clinical side effects and it listed water retention as a side effect. Wouldn’t this be the cause and NOT an allergic reaction? Also, if your answer is a “yes” could this also be the reason for the weight gain which is also listed as a possible side effect or would that be caused by an entirely different mechanism?

Have you seen this “puffy face” thing in any patients? If yes, is it common? And if you have, does the side effect remain as long as you are using minox or does your body eventually acclimate? Finally, if one did develop this, does the symptom last the whole day or does it abate after so many hours of last usage?

Water retention seems to be present in 7% of people starting on the minoxidil therapy. There are reports of weight gain as well. Most of the severe side effects come about when minoxidil is taken in pill form for the treatment of high blood pressure and the reports do indicate cardiac side effect, fluid buildup around the heart, etc.

As some of the minoxidil is absorbed through the skin, I would expect that the systemic dose should be less when used topically, but I can imagine that in some people absorption could be very high and the sensitivity to this drug high as well. Best to stop the medication and see a doctor in the case that this may be pointing to some silent heart disease and very early congestive heart failure.