Willow Water was first discovered in the 1100s by monks in the north west of England. They noticed the healing effects of an underground spring that they found, and promptly declared it to be holy water.

Nearly a millennium later, and science has finally given us an answer as to why this particular type of water is so good for you. As the water runs into the spring, it picks up mineral deposits from ancient willow trees, including a compound called salicin. Salicin is a natural anti-inflammatory found in willow bark, which provides relief for minor aches and pains and boosts the immune system.

Salicin also combines with the high levels of calcium in Willow Water to give your skin a boost, as well as strengthen your bones and teeth.

According to the folks over at Willow, all it takes is six weeks of drinking Willow Water for your skin to be noticeably healthier. If you don’t feel positively glowing and radiant after that month and a half, they’ll give you an extra six weeks’ worth of water completely free.