About 3 months ago I decided to quit taking Creatine supplements as part of my weightlifting diet. I've always believed that Creatine increased the prevalance of Acne on my adult skin. I recently discovered a study which confirms my suspicions:
Conclusion: "After 7 days of creatine loading, or a further 14 days of creatine maintenance dose, serum T levels did not change. However, levels of DHT increased by 56% after 7 days of creatine loading and remained 40% above baseline after 14 days maintenance (P < 0.001). The ratio of DHT:T also increased by 36% after 7 days creatine supplementation and remained elevated by 22% after the maintenance dose (P < 0.01)."
I think that given that the consensus is that DHT is directly responsible for sebum production, this study provides evidence that Creatine supplementation may increase DHT levels and therefore be a contributing factor in the development of Acne.
In the last 3 months I too have noticed a reduction in oiliness since I stopped supplementing creatine.