Excellent brand of Vitamin B12. I was getting side effects from another brand in sublingual form of B12 that I was taking so I switched to Quantum Nutritional Labs brand after my daughter recommended it. I am very happy with the results my B12 has gone up after confirming it with lab work and I definitely have more energy without any side effects. The delivery and packaging was awesome and quick and they package the bottle of B12 in bubble pack so it doesn't get broken or destroyed during the delivery process. I highly recommend this brand of Vitamin B12 because it is the purest form of Methylcobalamin without the side effects!