<<Disclaimer: Verify this information before applying it to your situation.>> Thanks to all who responded. Here are most of the replies. General opinion is that you can't really do any damage with once a week injections. Lisa Zafar The injectable B-l2 dosage is l ML (I000 MCG) monthly; however I can't tolerate that big a blast of it at one time, so I take 25% of the dosage weekly. My doctor told me that would be fine and he is pretty advanced with this sort of thing. BTW the injectable form of B-I2 is the easiest to absorb and the best way to take this vitamin. I've had to do B-12 shots since 1986 and it's always been 1 cc. For the most part, it's been once a month. My newest doctor, though, said to do them twice a month or even weekly if I felt I needed it. There's no possibility of damage from too much B-12; the body just excretes it. If you don't need it, you really just peeing it away (to be blunt). I've been getting B12 and Folic Acid (very necessary together) shots since 1970. Sometimes when I'm really really sick I get them daily, but usually once a week or so. The doseage my mom just got from a doctor is: B12 1cc, Folic Acid 1/3 to 1/2cc, B complex 1cc I have been taking self administered B12 injections for about 6 years. My initial prescription was for .2cc of folic acid and .8cc B12 once each week. About half of the amount present in a deep muscle injection leaves the body through the kidneys each 24 hours (1/2 the first 24 hours, 1/2 of the remaining amount the second 24 hours, and so on). After about 4 days, there is not much of the original injection remaining to worry about. More than 1cc per week is probably too much unless you notice some positive benefits from doing so. 1cc (or less) every two weeks would be a good dosage for long term use. Most persons need the B12 as a booster for impaired absorption rather than as a complete replacement for absorbed B12. If your ability to absorb B12 is completely compromised, you will definitely need weekly injections Lisa, I take b-12 in the form of "nuggets" that dissolve under the tongue and are absorbed there without going through the stomach. Each nugget is 1000 mcg. They are put out by Solgar and are available without prescription at good sitamin and supplement stores. I order them from L & H Vitamins under the brand name of Cambridge, but that is the same as Solgar. If you are interested and can't find them in your part of Upstate New York, let me know and I'll send the address of L & H. A lot cheaper and far more pleasant than shots, and can be taken daily. Water soluble, so no problem with taking too much. I think as a nurse it would depend on how low your hemoglobin and Iron studies are. I think your NP should have given you proper doage direction. However usual dosage is ....1000mcg B12 , 1 cc IM per month I took 1cc of each folic acid and B12 in shot form weekly for about 6-7 months or so, then I have been on that same dosage (1cc folic acid and 1cc B12) for an everyother week regimine for the last 2 years. For awhile I took that same dosage every 3 weeks, but I feel better on everyother week. You don't want to take more than what you need. My blood was monitored alot at the beginning, and to keep everything in check and in the normal range, every 2 weeks seems to work just fine. All I know is that I don't absorb the B12 and folic acid by mouth. I was taking loads of it by mouth and it did absolutely nothing for me. Perhaps monitoring your blood every few months for awhile is way to go. >Lisa- The proper dose is 1000micrograms once monthly. Some people take it weekly but no harm except to the pocketbook. i have pernics anemia and i give my self b-12 and folic acid 3,xs a week 1/2 cc of folic acid and 1cc of b-12