I started taking these about a year ago. I read that you should start your dosage small until your body can get used to the extra vitamin intake. As of late, I take 3 daily, so 3000 mcg, and I will continue for about another year before I hit the 5000 mcg mark. This natural vitamin has helped my hair, skin, and nails be the healthiest they can be. My nails are stronger, my hair shinier, and my skin has been acne free (with a few stress breakouts here and there). Overall, I am happy I have found a great product. Just make sure you are drinking a lot of water!