Numerous cold therapy benefits are provided by menthol-based topicals which provide effective and targeted pain relief
Topical analgesics can play a key role in treating both acute and chronic pain, 1 and research has shown them to be convenient, safe, and effective 2. For many patients, when combined with chiropractic techniques, topicals can help alleviate pain, minimize soreness and make everyday activities easier to complete. Moreover, because they are applied locally, topical medications do not penetrate the bloodstream, which lowers the risk of side effects and adverse events compared to oral medications. 3
The ongoing opioid epidemic has brought even greater attention to the need for safer alternatives to pain relief such as hot and cold therapy benefits. Clearly, topicals can help deliver safe, effective and non-addictive treatments for managing pain. 4,5,6
Types of topicals
There are many factors to consider when selecting a topical analgesic, but the most important is the active ingredient. Some of the most common ingredients include: methyl salicylate, camphor, menthol, methyl nicotinate and capsaicin.
These can be available in a variety of formulations, such as gels, ointments, creams, lotions, sprays or patches. In general, topicals can be divided into the following categories: 7,8
Counter-irritants — These are medications that stimulate nerve endings to produce hot, cold or tingling sensations, which can override the body’s ability to sense pain. Menthol, camphor and eucalyptus oil are the most commonly used counter-irritants.
Salicylates — These contain ingredients similar to aspirin or NSAIDs, though typically in lower doses. These anti-inflammatory medications penetrate tissues beneath the skin to reduce swelling. They also inhibit pain transmission from sensory nerves.
Capsaicins — Derived from chili peppers, capsaicin serves as an anti-inflammatory and produces an analgesic effect by attaching to the skin’s heat-sensitive receptors. It lessens the activity of certain chemicals within nerve cells that are responsible for activating a pain response.
Working the peripheral
The pain-relieving mechanism of the action behind topicals can be complex. However, a basic understanding of the underlying biological process is helpful for any practitioner employing this method of pain relief.
Topical analgesics work by acting on the peripheral nervous system. Many researchers rely on the Gate Control theory of pain to explain the efficacy of topicals. This theory asserts that nerve fibers, or “gates,” control pain messages going from nerves to the brain. These fibers affect the amount and intensity of pain felt by an individual. By stimulating a nerve fiber to close, or at least narrow the gap, topicals can stop or at least lessen the flow of pain messages traveling to the brain to temporarily inhibit the perception of pain. 9,10
Topicals also work by interacting with transient receptor potential channels (TRPs). These receptors are found on most cell surfaces, including nerve fiber cells, and mediate a variety of sensations, including pain. Topicals work by disrupting the pathways of certain pain receptors, depending on the active ingredients, which temporarily shuts down the transmission of pain messages. In addition, some TRPs associated with pain also respond positively to pressure, so the very act of applying the topical provides additional pain relief. 11
Menthol: the science of cool
As a counter-irritant, menthol imparts a cooling sensation that stimulates nociceptors and then desensitizes them. Clinical studies have shown that it is safe and effective for treating a variety of painful conditions, including musculoskeletal pain, sports injuries, neuropathic pain and migraine. For instance, a study published in the International Journal of Sports Physical Therapy found that a menthol-based topical was more effective than ice for relieving soreness and discomfort associated with delayed-onset muscle soreness (DOMS). 12
While menthol’s use as a topical analgesic dates back to ancient times, it’s only recently that researchers have come to understand the specific molecular mechanism behind its pain-relieving properties. Menthol works by binding with temperature-sensitive receptors called TRP melastatin-8 (TRPM8). Known as “the menthol receptor,” TRPM8 is what causes the brain to perceive cold sensations and is activated by temperatures below 26°C as well as a variety of chemical agents. When menthol acts on this receptor, it causes the release of calcium ions that are believed to help moderate pain signals. 13,14
When selecting a menthol-based topical, it’s important to consider the product’s concentration of menthol. Too little menthol can be ineffective for pain relief, while high concentrations can be irritating to the skin and/or have a strong odor that patients find offensive. In addition, the benefits of menthol are not directly proportional to the concentration. In one study, researchers applied topical menthol to study volunteers in three concentrations (0.5%, 4.6% and 10%). The cooling effect of the menthol was significantly more pronounced with the 4.6% concentration than either the 0.5% or the 10%. There is a new professional-strength topical with an optimized menthol concentration (7.4%) that appears to achieve a good balance of imparting the right amount of cold therapy benefits for effective pain relief without being overwhelming or irritating. 15
Aside from the active ingredient of the topical, additional ingredients like anti-inflammatories can augment the primary analgesic effect, while scents can mask the strong menthol odor. For instance, the optimized menthol topical also contains Arnica montana extract, a natural anti-inflammatory that is often used to treat pain and swelling associated with bruises, aches and sprains.
The addition of tangerine oil, which is associated with healing and calming properties, gives the product a light, citrus scent. A more pleasant odor increases the likelihood that patients will comply with the topical regimen to get the maximum pain relief and cold therapy benefits.
Benefits for athletes
Using topicals in conjunction with chiropractic techniques like Instrument-Assisted Soft Tissue Mobilization (IASTM), percussion therapy and shockwave therapy can help athletes of all levels maintain their health, improve performance and prevent injuries.
When working on athletes, whether it’s treating an injury or doing preventative maintenance, the goal is to improve tissue vitality. The aim of these chiropractic techniques is to create micro-traumas at the site of pain or soreness, which increases blood flow and triggers a response that stimulates the body’s healing process.
For preventative maintenance, the athlete can apply the topical themselves to help reduce DOMS and use their own self-care massage techniques like percussion massagers, rollers and massage balls. This can speed up recovery, improve performance and prevent injury.
Improved athletic performance comes from proper recovery, and both topicals providing cold therapy benefits and chiropractic care can help accelerate the healing process. From professional athletes to weekend warriors, the right combination of topicals and chiropractic care can play a key role in helping them get the most out of their bodies.
CHAPPY WOOD, DC, is the owner of Marin Spine and Wellness, a chiropractic and sports rehab center in the San Francisco Bay Area. His primary goal is to provide the latest techniques and modalities to help people get back to their active lifestyles. He can be contacted at marinspineandwellness.com.