No, it is not recommended to take it without consulting a doctor. Knee problems can arise from conditions such as osteoarthritis, ligament injuries, or inflammation and require proper medical evaluation. Although this supplement is marketed for skin, hair, nails, and bone health, it is only supportive and not a treatment for knee pain. A doctor can assess your condition, identify the underlying cause, and advise whether collagen is appropriate and safe for you. Without medical guidance, the real issue may be missed and effective treatment delayed.