I have been taking this product for 3 years and it's made a huge difference to my life! Before being diagnosed with a b12 deficiency I was suffering with headaches, anxiety and felt completely exhausted all the time. My levels were checked by Drs a few weeks after starting these (initially 2 a day reducing to 1 a day after 6 weeks) and level was back within good parameters. (& has stayed there!) The fruity flavour is very pleasant & means I don't have to have any nasty injections!!