These ancient peoples knew of the effectiveness of White Willow Bark through their own experience, yet low and behold, thousands of years later, discoveries were made concerning the active agent within willow bark: Salicin. This discovery would later evolve into the creation of a now well known drug: Aspirin which is commonly used to help manage pain & fevers.
The image below shows a brief timeline of the discovery of Aspirin.
Historically, we know that Pedanius Dioscorides, an ancient Roman who wrote a guidebook of medicines, described willow bark as a remedy for stomach ache, tuberculosis, and as a contraceptive. He also said that willow bark could remove corns and calluses. He did so by burning willow bark, soaking it in vinegar, and then rubbing it on the affected area.
Celsus was the author of the first medical book to ever be published (albeit it was published centuries after his death) and was another Roman medical writer who mentioned Willow Bark. He states in his writings that a warm willow pack or poultice could treat a womb or bowel prolapse. Celsus advised to push the womb or bladder back into the body and then wrap a warm dressing of Willow Bark around the outside of the body.
It is common to want to link Hippocrates with prescribing White Willow Bark, connecting him with its ancient medicinal history. Yet when you look at Hippocrates' actual writings, there is only one single reference of him using Willow which was that he burned Willow leaves in order to help a miscarriage move out of the uterus. In Hippocrates' writings, this was the only mention of using willow as a drug.
Many cultures have successfully used the Willow Tree, including the Ancient Chinese, who used willow shoots and poplar bark to treat rheumatic fever, colds, hemorrhages and goiter.
It is thought that Salicin, in combination with the bark's flavonoids is what is responsible for its pain relieving and anti-inflammatory properties. Salicin, Willow Bark's main active chemical constituent, was first clearly identified in 1828 by Johann Buchner, a Professor of Pharmacy at the University of Munich, who was able to isolate a small amount of bitter, yellow, needle-like crystals from the bark. He named this substance Salicin, even though two years earlier in 1826, Brugnatelli and Fontana, two Italian Scientists, actually obtained Salicin in a much more impure form. In 1829, a French chemist, Henri Leroux was able to improve the extraction method and create 30gms of Salicin from 1.5kg of bark. And, a few years later in 1838, Raffaele Piria, an Italian Chemist, was able to create a pure substance he named "Salicylic Acid".
So Leroux was responsible for extracting Salicin in its pure crystalline form and Piria was able to produce Salicylic Acid in its pure state. This early research was pivotal in allowing the Pharmaceutical company, Bayer, to produce and patent "Aspirin", giving it a 17-year monopoly over this new effective pain relieving drug.
I personally have used White Willow Bark capsules as a replacement for Aspirin when it comes to treating moderate to severe menstrual cramps with general success. I will alternate between White Willow Bark capsules some cycles and Cramp Bark capsules other cycles. Phoenix has used White Willow Bark Spagyric Tincture to eliminate headaches, reduce pain after splitting his bottom lip open during a forestry accident, to help break a fever, as well as taking it as a spagyric initiatic tincture early on in his Alchemical pathways.