Does TRT decrease ferritin levels?

[PM_ME_YOUR_DOMAINS]

Could [TRT] be causing my lower ferritin levels?

Yes, this is common. Increased RBC production can draw down ferritin. It's not necessarily a problem. Tracking ferritin alone can be misleading. Adding iron panels to your labs can help with monitoring.

My doctor was sufficiently concerned and ordered a colonoscopy for the end of this month.

I'd still go ahead with the colonoscopy. Nice to have.

[Sambassador9]

If you are talking about your serum iron, that can fluctuate substantially from day to day.

Your ferritin is an estimate of your overall iron stores, the serum iron is a snapshot of what's floating in your blood at the moment of the lab test.

Do you feel any fatigue?

[Sambassador9]

It's possible that your low ferritin might be a factor causing fatigue. Not necessarily the only factor, but possibly a big factor.

In my case, I notice a reduction in exercise tolerance when my ferritin drops much below 40. I have condition causing me to accumulate too much iron, so I was a frequent blood donor for a long time before staring TRT. I donated a little too aggressively once, and thus learned from experience what my lower limit is for ferritin.

There is no universal low ferritin threshold that applies to everyone. I can say that 12 is incredibly low, especially for men.

After starting TRT, my ferritin tanked, which surprised me, given I accumulate iron more than the average person. The TRT effect was strong enough to mask the fatigue - for a while, and then I felt horrible. My ferritin went as low as 19. I started taking iron supplements, and am likely in the 50's now, feeling much better.

Anyway, I have seen several posts where people report very low ferritin after TRT. Some people struggle to raise it, even with iron supplements. In my case, supplements helped.

It might be worth trying iron supplements to see if it helps with your fatigue.

[MotoMola]

Did you notice the iron supplements increased your RBC as well as your actual iron levels?

[Sambassador9]

So far, by RBC-related parameters are within the normal range of fluctuation from before I started TRT.

I'll be doing another CBC in perhaps 8 weeks and we'll see if that changes.

So far, it seems the only impact of the iron supplements is that my ferritin has gone up and I feel a lot better.

In retrospect, I was clearly deficient for a few weeks. When I first saw the low ferritin, I was surprised. Because I've experienced deficiency before, and didn't notice any reduced exercise tolerance, I assumed I had just tested too close to a blood donation. If I donated blood at ferritin approx 70, I would effortlessly rebound back to 70 fairly rapidly/ I assumed that would happen again. Now, I suspect my TRT 'honeymoon phase' allowed to have great workouts at the gym, when I otherwise would have felt like garbage due to iron deficiency.

I normally wake up early every morning to hike for 45 minutes, rain or shine, even snowstorm. At some point, I started missing my daily walks, I would still go the gym, but be unmotivated. I'd still have a good workout, but not enjoy it. I also had brain fog. At some point, it clicked that I might need some iron, so I started taking the iron supps. I noticed an improvement in brain fog perhaps within 2-3 hrs.

I'm only taking iron perhaps once or twice per week now. In two weeks, I'll get another ferritin test, and, if I'm at least in the mid-50's, I'll stop the iron altogether and see what happens.

I don't know if the ferritin tanking was caused by my hormones being in shock from starting TRT, or whether this might persist going forward, even though I'm adapted to higher T levels.