Wood Lock® oil is a topical analgesic made from menthol, camphor, turpentine, cinnamon, and peppermint, which gives it a distinctive scent. It also contains methyl salicylate, a pain-relieving compound that's related to the active ingredient in aspirin, and a proprietary blend of herbs. It commonly is used to treat sore muscles and joints, to relieve back pain and to ease arthritis. Though it can be effective, it may cause side effects, especially if used improperly. There are a number of related products with similar formulas, but without the same mix of herbs.
This oil is most commonly used as a topical painkiller for muscle cramps and soreness, general joint pain, and tendon pain. It's very commonly used to treat arthritis pain, and can help temporarily increase circulation in the area it's rubbed on. It can be applied before or after workouts to reduce muscle soreness, but some people get a rash if they put it on before working out. It can also be used to treat headaches and clear out the sinuses. In Traditional Chinese Medicine (TCM) terminology, it increases the heat of an area, which can soothe soreness and improve the flow of qi, or energy, in an area.
Wood Lock® oil can be rubbed into the affected area like a liniment, or it can be applied using acupressure. To do this, a person puts two or three drops of oil on the skin, and then presses the oil down into the skin using a few fingers, sometimes rubbing in small circles around the area. This is generally done for about 15 minutes. It's best to spot-test the oil on a small part of the skin before using it to check for possible allergies.
Possible Side Effects
Some of the ingredients in Wood Lock® oil can cause skin irritation, particularly to delicate areas like the skin around the eyes or the genitals. It is important to wash the hands after using it to avoid accidentally spreading the oil to any mucous membranes. It should not be used on any area where the skin is broken, and can be poisonous if swallowed. Repeatedly rubbing large amounts into the skin can also be dangerous, since it's possible to fatally overdose on methyl salicylate that way. This is also true for other products containing methyl salicylate, like Bengay® ointment.
There are a number of products with similar ingredients, including Chan Yat Hing® Medicated Oil and White Flower oil, off of which the recipe for Wood Lock® oil was based. Both can be used to relieve minor aches and pains, though Chan Yat Hing® oil has much less methyl salicylate than Wood Lock® oil. There are also several knock-off versions, which often come in similar packaging, but may have completely different ingredients.
In the US, a popular form of this oil was once recalled due to "improper packaging." The bottle had a cap with no child protection devices, meaning that young children could encounter the bottles and ingest dangerously large amounts of methyl salicylate and camphor, both of which are poisonous when ingested. This recall was not due to any reported injuries, but rather a proactive step to protect children.