Does Finasteride use cause Vitamin B12 deficiency ?

I have low Vit B12 as well.

What a pile of crap this condition is, I was vegan for almost 2 years and my B12 was in range, and after PFS is below range despite I eat plenty of meat and eggs.

I was prescribed methylcobalamin, but I’m quite scared of sides.

Out of curiosity: why do you prefer injections over pills?

Pretty much the same symptoms you have plus vibrating sensation

I’m taking hydroxocobalamin once a week
Hope it works for you too

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Do you think Idroxycobalamin is better than methylcobalamin or cianocobalamin?

I’m low in B12 as well and with several neurological symptoms, but I keep procrastinating because I’m afraid of sides.

I don’t know if there’s any difference tbh but hydroxycobalamin is what I tried
Also injections is more absorbable almost 100%

Do you still take it? Have the effects faded?

Yes It’s my 3rd week on it
I can’t say it’s faded but definitely got better and not as annoying

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Vitamin B12 injections are recommended for very severe deficiencies, such as mine. For me, B12 from dietary sources or tablets is insufficient because the digestibility is low. It is caused by the gastric intrinsic factor (see here: In other words, I would have to eat beef liver and take B12 tablets for months or years to get a good result. In the injection, you will find a much higher dose of vitamin B12, which is also better absorbed. For example, the bioavailability of 1 mg of intramuscular cyanocobalamin is around 10-30%, and the bioavailability of hydroxocobalamin is even 70% (please kill me, but I can’t find the sources right now). So you can get as much as 700 mcg per day from one injection, while oral sources can give you a maximum of 10-20 mcg per day (assuming you are taking B12 all day long at intervals of several hours). As a result, one method will allow you to replenish your B12 levels in a few weeks (assuming two injections a week), and the second method will probably allow you to get a few months or years. I would like to add that “the total amount of vitamin B12 stored in the body is about 2–5 mg in adults” ( So, with a severe deficiency, intramuscular therapy appears to be necessary.

Oral liquid methylcobalamin doesn’t work for me, but that’s probably because I’m too deficient (and, of course, because of the low bioavailability of this form of B12). Besides, I would be wary of methylcobalamin as it is a methyl donor, which may be bad for some of us (look here: -b-vitamins / 32044 and also here:

Well … good luck and keep us updated.

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Additionally, I’d stay away from cyanocobalamin. In the oral form it is very poorly absorbed, and in the form of injections it is to some extent poison (cyanide in a small amount), and also leads to the reduction of glutathione. Every time I was given a cyanocobalamin injection, I was temporarily increasing brain fog or headache. At the same time, I did not get a good effect. So my B12 deficit must have been really high, since I have such a low level despite taking 1 mg of cyanocobalamin several times a year (then I thought that if I eat meat or eggs 2-3 times a week, I would only need a B12 injection every 3 months to maintain a good level).

Thank you.

I wonder why we can’t absorb it from food by the way.

GI inflamation? Gut disbiosis? Go figure.

That’s a good question. At the moment, apart from flatulence, I don’t have any major intestinal problems (no constipation, no gas, no stomach or bowel pain). Perhaps I am genetically burdened in some way, because I remember that 15 years ago I ran 10-15 km a day, after some time I had to supplement with vitamin B12 (I had a low B12 result then, but still normal). PFS is such a strange condition that it’s hard to say what might be causing it. And look at how different the methods of recovery or improvement are - there is no one that fits all of us.

Thanks for the kind words. I will keep you updated in this thread.

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I have none of the symptoms you listed (a little flatulence, that’s it), but I have worms in my gut and dysbiosis.

It could be worth taking a look.

If my financial situation improves, I’ll have my intestines checked. Although I would be surprised if my intestines were in bad condition (I have done a lot of water fasts and juices, and also eat very healthy, with very rare exceptions).

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Again, good luck man :slight_smile:

When are you starting your supplementation?

As soon as possible. I think my vitamin will reach me next Tuesday, maybe Wednesday. And I hope that the Germans packed it so well that it will not be damaged in transport. Vitamin B12 should be stored at room temperature, up to 25 degrees Celsius (thank God for a cool spring in Central Europe).


Just wanted to let you know that I got my first injection of 1.5 mg of hydroxocobalamin (exactly hydroxocobalamin acetate) yesterday. This is a bit surprising because this form of B12 worked like sleeping pills for me. Even now, when I wake up, I am still very sleepy. Besides, I have a slight headache (but much less than after the cyanocobalamin injection). Surprisingly, increased sleepiness, which is not an uncommon effect of this treatment, was also experienced by @lakehouse. In any case, I am going to continue the therapy (2 injections a week for 3-4 weeks, and then one injection for 1-2 months) and wait for the results - I hope positive.

I have mid-normal range vit B12 and still supplementing it, because i suffer of

So, as I understand correctly, for you this type of anemia is caused by a deficiency of folic acid (I assume that then folic acid supplementation is more important to you than vitamin B12)? If so, what form do you take folic acid in? This is important because a lot of people here have a problem with methyl.

Folic acid and/or vit B12 deficiency causes megaloblastic anemia. But my folic acid is just higher thaan normal, so to me vit B12 (is normal mid-range) should be supplemented