Hair tonic

From Tardis Wiki, the free Doctor Who reference

Hair tonic was a drink available in the 42nd century used to combat hair loss. Ood Operations chairman Klineman Halpen used it regularly. This was used against him by his Ood servant Sigma to turn him into an Ood as a punishment for his cruel treatment of the Ood slaves. He replaced the tonic with Ood graft suspended in a biological compound. (TV: Planet of the Ood)