When one walks into any reputable healthcare store, there is often a myriad of topical creams and ointments designed to reduce inflammation and pain. The variety of product offerings should help the consumer find a product that best interacts with their injury or ailment while providing an effective level of relief from pain. The question every pain suffers asks is “will this product work for me?” However, the real question should be “what active ingredients will relieve my pain?”
There are many cold therapy topical products that contain menthol as their main active ingredient. Used by many physical health professionals, they have shown the benefits of using cold, topical solutions for pain relief while addressing issues of inflammation. Traditional thinking is that the pain-relieving mechanism of action of menthol results from a counter-irritant effect. A process was first described by Melzak and Wall is known as “gate control” or “gating,”
It was discovered that a counter-irritant has an effect of overriding noxious pain signals traveling to the brain. The process modulates between pain-transmitting and non-pain transmitting neurons. Laboratory researchers have also discovered that menthol stimulates the TRPM8 cold receptors. Even though it has long been accepted that cold application can induce analgesia, the mechanism of action was not understood.
Further study of these specific TRPM8 receptors is activated through the cooling effect of menthol functioning as a topical analgesic, providing pain relief to the user. As the mechanism of action becomes better understood, it further explains why some studies have been able to show an equivalent level of pain relief using a menthol product like Biofreeze for the treatment of back pain with the same efficacy of a TENS system.
Arnica is another common active used in a variety of products. Arnica has proven to reduce muscle swelling, while other ingredients such as calendula gently soothe the skin. Hypericum is incorporated for stress reduction and peppermint for its cooling and anti-viral properties.
Other products may use copper as its base for its anti-inflammatory properties while reducing pain and swelling. In 1939, a German doctor, Werner Hangartner noted that copper miners from Finland never suffered from arthritis although rheumatism was rampant. The doctor went on to use copper to treat many of his patients.Copper is being incorporated into many products for its antimicrobial activity and its strong positive attributes for the treatment of swelling and pain.
Camphor is another popular compound used in many topical preparations as camphor relieves pain and reduces itching. Camphor increases local blood flow and acts as a “counterirritant,” which reduces pain and swelling. It is important not to apply camphor to broken skin because it can enter the body quickly and reach concentrations that are high enough to cause poisoning.
Preparations containing methyl salicylate (oil of wintergreen or wintergreen oil) can provide some relief from pain. However, it should be noted that studies have shown that products with methyl salicylate are more effective for acute versus chronic pain.
Stinging nettle has fine hairs on the leaves and stems. These hairs contain irritating chemicals which are released when the plant comes in contact with the skin, but the hairs are painful to the touch. When the stinging nettle comes into contact with an area of the body with pain, it has been shown to decrease the level of pain. The mechanism of action is from the reduction of inflammatory chemicals levels in the body, and by interfering with the way the body transmits pain signals.
Compounds that have isolated acetylcholine histamine and 5-hydroxytryptamine from the stinging nettle and combine it will isopropyl alcohol have shown to provide some relief from arthritic pain. It is the combination of the nettle extract and alcohol that promotes the excretion of uric acid from the body, creating a cooling and pain relieving the sensation.
Hamamelis virginiana is one of the witch-hazel species that reduces swelling and acts as an anti-inflammatory when applied to the skin. There are no reported reactions to this compound when used topically.
After consulting with your therapist, patients and end users should take the time to read the label on each product to determine the action that is contained. As we react differently to different active components, the more we understand how our body responds, we will be able to achieve some true pain relief.