There was a report nearly twelve years ago that indicated that conditioners contribute to baldness and hair loss in men. Ok for women though. The basis for this was that in men the scalp oils contain testosterone and that the dry hair absorbs it. If the hair is conditioned (moisturised with oils) the hair cannot absorb the scalp oil and the excess testosterone damages the hair follicle. This was discovered during placebo tests for anti-baldness products where the placebo was a conditioner.
The final result was that using a “baby” shampoos and massaging the scalp led to nearly as much recovery as the various hair re-growth products. Although things like ReGain were approved, sixty percent of the placebos in tests that did not uses conditioners had as much re-growth success.