tl;dr: Taking fluoxetine (an SSRI antidepressant) inhibited my body’s ability to regrow bone in order to heal a fracture in my collarbone. When my mother first discovered the connection and we were both googling like crazy, I couldn’t find any first-hand accounts of others who have been through this. So, here’s my story. Maybe it will help someone someday on the other side of the interwebs who can’t figure out why their bones aren’t mending properly.

I fractured my left collarbone at the beginning of June, an injury that I definitely don’t recommend. The short story is, I was biking with a friend and we both got hit by a car. He fractured a wrist and a rib, while I fractured a collarbone and sprained an ankle.

My bike did not fare well in the accident.

Turns out shoulders, and collarbones in particular, are pretty useful in life. I couldn’t lay down on my back (even to sleep) for a full month. I also couldn’t do things like put my hair in a ponytail (see exhibit A), pull shirts on over my head, or wash my right armpit. Super inconvenient, but I was told by multiple doctors that I’d be able to start using my left arm pretty normally again in 6-8 weeks, which is a bummer but not insurmountable. Plus I had a lot of Arrested Development to catch up on.

When you can’t do your own hair and all your roommates are guys

And then my 5-week x-ray showed zero progress. Flup. Neither my orthopedic doctors nor my mother (who is a family doctor) nor I could figure out why my collarbone wasn’t healing at the normal rate. As a super active and generally healthy person in my early twenties, I’m not usually on the way low end of the bell curve when it comes to health and wellness. Upon seeing the x-ray, I was asked by multiple doctors at Kaiser if I smoke, because apparently I present as a chronic chain smoker (I’m not). I was also asked by my doctor if I have an autoimmune disease that could be slowing down the healing, which I feel like would probably be in my health file if I knew about it. Not super useful questions. I was then basically told that some people suck at healing bones and I must be one of them. Not a comforting explanation.

After a week of frustration and worry, my mother finally stumbled on what we think is the key. I currently take fluoxetine, an antidepressant, which has been linked to slow bone growth and an increased risk of fracture. I’m classified as a “chronic user” since I’ve been on it for more than six months, so the medication has had more than enough time to work its way through my system and affect my bone metabolism. It’s an annoying catch-22, because I’m left deciding between my mental and physical health, but at least I have a satisfactory explanation for my lack of healing progress.

Quick intermission on the serious stuff to look at a close-up of the bike frame. Note the sheared carbon fiber fork in the bottom left. The car made a pretty solid impact with my bike frame.

I decided to do an experiment. My general habit is to take my meds every day, spacing out my weekly dosage evenly over the course of the week, but my psychiatrist said that it’s fine to front-load my medicine in a week, taking all of it in two or three days and then none at all for the rest of the week. So, just to see what would happen, I stopped taking the fluoxetine for 5 full days. And my shoulder felt GREAT. Before, I was in pain most of the time and didn’t have great range of motion with my left arm. After just three days off the meds, I was able to walk around without any form of brace, which I’d needed since the accident. It seems pretty clear that my collarbone made a lot of progress in those 5 days without the fluoxetine. However, this is a confusing result because fluoxetine has a pretty long half-life. It should still be in my system in pretty large quantities, so I’m not sure if this result is just a fluke.

No experiment is complete without secondary validation, so then I started taking my meds again for a few days, bumping up the dose so that I’m still taking the correct weekly dose (as my psychiatrist recommended). As expected, my shoulder started feeling worse. I still had the new and improved range of motion, but the pain was back and triggered a lot more easily than it had been at the end of the 5-day period when I wasn’t taking the fluoxetine.

I’ve come to the conclusion that in my case, the antidepressant fluoxetine, an SSRI, was directly hindering bone growth as my body attempted to heal my fractured collarbone. However, when my mother first figured out that these meds could be the reason for my slow progress in healing, and I reached out to the three orthopedic doctors that I’d seen to ask about it, none of them really believed me or gave it a second thought. They all wanted to just wait and see if the 8-week x-ray would be better than the 5-week x-ray. As a super active person that really wants to get back to climbing and skiing and soccer and yoga and camping and all of the fun outdoorsy things, “wait and see” doesn’t sit well with me. I wanted to know what was wrong, and what I could do to help speed things along.

My mom and I did a ton of research and consulted with other doctors. She found one colleague that had heard of the connection and recommended stopping medication if possible. We found a few different journal articles that pointed to a legitimate correlation between fluoxetine and a lower bone metabolism (i.e. ability to regrow bone cells). That coupled with my (not-super-scientific) experiments are enough to convince me that the medicine has made a different in the speed that my body is able to heal my bone fracture. I’m working with the doctors to figure out the best course of action, but at least I have a lot more information now.

It seems crazy to me that none of the three orthopedic doctors I saw had heard of the correlation between antidepressants and slow bone growth, but hopefully now they’ll know for next time. And so will anyone reading this that’s worried about slow bone healing.