I have struggled with low ferritin for basically ever. Down to 3 or 4 at the lowest. Once I managed to get it as high as 18, and then it dropped again. What was extra annoying was the docs who would say "oh that's normal for women" when I was not getting my period due to being on birth control. People on reddit are always talking about infusions, but my doc told me no. They're only done in hospital here, and as a result, only in emergency situations.

I was on Feramax daily for 2 straight years with no improvement. My ferritin was at 7. Doc told me the usual empty stomach/vitamin c, tested again after doing that for 6 weeks it was down to 6. Had upper & lower GI scope to see if there was a reason I wasn't absorbing. They found nothing.

But! I am pleased to report that last time I tested, my ferritin was 82!! And I feel more full of life!

What worked for me:

• 2x Palafer (each capsule contains 300 mg ferrous fumarate, equivalent to 100 mg elemental iron) every second day, with vitamin C, 2 hours after last food/drink, 1 hour before consuming anything else (water is ok). I took it around lunchtime, because I couldn't face waiting an hour for morning coffee.
• Food source of heme iron every single day. Beef, liver, oysters, mussels, lamb, black pudding, you name it. Doesn't need to be a huge amount or at every meal, even just 2oz a day is fine. Tried heme supplements but they didn't have the same effect as actual meat.
• Separately from the iron, supplement in the morning with C, B complex, B12, D, and E. At night I take Magnesium.
• Also, drink lots of water generally.

Basically, my body just did not absorb as much iron from either food or supplements as it did from both together. It's like eating heme-rich foods got my body primed to accept the supplements or something.

Just wanted to share in case this helps someone else!

ETA: One last thing: when you're buying vitamin C to take with iron, make sure it's ascorbic acid, not calcium ascorbate!