HAIRMETTO Oil has been a customer favorite since 2014. It's a powerful combination of 6 different oils - no water - and as such, has the ability to penetrate deep into the saturated roots overnight; delivering the antioxidant nourishment to the follicles. Since its consistency is 100% oil, the texture on the hair may not be compatible to leaving it on during the day. For those who prefer not to sleep with it in every night, the Serum is a water-based alcohol-free gel, which can be applied and styled for regular daytime activities. It contains the same DHT blocking saw palmetto extract, combined with Stinging Nettle and Peppermint oils for an effective scalp treatment while you work and play. If you should choose the Serum, we highly recommend the Oil be used once a week at night to provide that deep penetration to the roots, especially if used in conjunction with the Dermaroller which opens up and prepares the scalp to receive the nourishment. Always apply your treatment to a clean scalp for best results.