Black heads are caused due to mineral imbalance due to fluid overload. This can be cured in 15 days by hydration dehydration cycles.

****In brief hydration dehydration cycles is as given here -****

Day 1 - Drink 150200 ml water every hour from 7 am to 6 pm. No other fluid/ liquid.

Day 2,3 - Drink 150200 ml water 3 times only during the day. Total fluid intake 450600 ml in the day.

Repeat for 23 weeks.

Fluid overload is one of the basic reasons of low resting metabolic rate.

For explanation of the above read my blog.