Vitamin B12 (cyancobalamin, Cbl) has two active co-enzyme forms, methylcobalamin (MeCbl) and adenosylcobalamin (AdCbl). This product contains methylcobalamin. Both MeCbl and AdCbl are essential and have distinct metabolic fates and functions. MeCbl is primarily involved along with folate in hematopiesis and development of the brain during childhood, whereas deficiency of AdCbl disturbs the carbohydrate, fat and amino-acid metabolism, and hence interferes with the formation of myelin. It is important to treat vitamin B12 deficiency with a combination of MeCbl and AdCbl or hydroxocobalamin or Cbl. European Journal of Clinical Nutrition. 69 (1): 1–2

I have used these off/on over the years. First, this is a lot of B12! It will definitely increase the amount of B12 in your system and fortunately B12 dissipates so you can't really harm yourself if you get too much. My main complaint is the quantity/cost. You used to get more for less, but I guess you can say that about a lot of things....

I carefully read product information listed on the website on all of my vitamins to determine the country of origin. You have erroneously listed USA as the country of origin for components and assembly. The listing on the bottle is China. I DO NOT appreciate the "bait and switch".

Great supplement, I have trouble absorbing vitamins and many B vitamin supplements make me nauseous. But because this one is sublingual it gets easily absorbed and for whatever reason, it doesn't make me the least bit nauseous, even on an empty stomach. AND...it comes out to $1.90 per month. You can't beat that!

Many people like myself are allergic to the chemical sweetener Sucralose, not to mention all the people getting bad reactions from it, so why in the world did Sams choose to put this chemical in a vitamin of all things? Bad choice..product was returned.

Our doctor likes Vitamin B and recommends this for my husband.

Definitely gives you energy good quality

Excellent sublingual for everyday

I like to quick dissolve tabs and the chemistry level has raised on lab tests. It works.

Tastes good, dissolves quickly