I have been taking Dr berg's hair formula, but it only contains collagen type 1 and 3, now I am trying Dr. Emil's collagen capsules as this contains collagen type 2, I am 43 years old and have knee pain going up and down stairs, I have finished one bottle and am about to take a second one so I thought I would post my feelings on it. I did notice that Dr. Emil helps me, the knee pain symptoms are almost gone, which is strong, but the hair and nail growth is faster Dr berg's hair formula is more effective, so buying a collagen product still depends on what you need more, because Dr. Emil has more combined types, I would recommend choosing it to make life easier! Also effective