Tachykinins are a family of signaling molecules produced by your nervous system and immune cells that drive inflammation, transmit pain signals, and influence mood. The most well-known member is substance P, an 11-amino-acid neuropeptide involved in everything from chronic pain to stress responses to hot flashes. Reducing tachykinin activity is possible through several routes: topical treatments that deplete substance P from nerve endings, prescription medications that block tachykinin receptors, stress reduction techniques, and newer approaches like vagus nerve stimulation.
What Tachykinins Do in Your Body
The three main tachykinins in humans are substance P, neurokinin A, and neurokinin B. They work by binding to three types of neurokinin receptors (NK1, NK2, and NK3) on cell surfaces, triggering a cascade of internal signals. Depending on the cell type, this can mean releasing calcium stores that activate inflammatory pathways, ramping up cell growth signals, or producing precursors to inflammatory lipids. In simpler terms, tachykinins act as amplifiers. When they’re active, pain signals get louder, inflammation spreads more easily, blood vessels dilate and leak fluid, and smooth muscle contracts.
Substance P is especially active in pain-sensing nerves, the gut, the skin, and the brain. When nerve endings release it into surrounding tissue, you get what’s called neurogenic inflammation: redness, swelling, and heightened sensitivity that isn’t triggered by an infection or injury to the tissue itself, but by the nerves firing inappropriately. This is a key driver in conditions like fibromyalgia, irritable bowel syndrome, certain skin conditions, and chronic pain syndromes.
Capsaicin: Depleting Substance P Locally
Capsaicin, the compound that makes chili peppers hot, is one of the most accessible ways to reduce tachykinin activity in a specific area of your body. It works by binding to a receptor called TRPV1 on the surface of pain-sensing nerve fibers, forcing those nerve endings to dump their stores of substance P, neurokinin A, and several other neuropeptides all at once. The initial release is why capsaicin burns when you first apply it. But with repeated use, those nerve endings become depleted and can no longer send pain signals effectively.
In laboratory tissue studies, capsaicin exposure reduced substance P-containing nerve fibers by 57% compared to untreated tissue. For practical use, capsaicin is available over the counter in creams and patches at concentrations ranging from 0.025% to 0.1%. Higher-concentration patches (8%) are available by prescription. The key to making capsaicin work is consistency. The burning sensation typically decreases over the first one to two weeks of regular application as substance P stores become progressively emptied. If you stop applying it, nerve endings gradually replenish their neuropeptide supply and sensitivity returns.
Managing Stress to Lower Tachykinin Production
Psychological stress directly increases tachykinin levels. Research on stress responses has shown that stress-induced glucocorticoids (your body’s own stress hormones) upregulate the gene expression for tachykinins in skin cells and other tissues. In one study, even low doses of stress-level glucocorticoids induced substance P production from human skin cells and boosted inflammatory cytokine output. This creates a feedback loop: stress raises cortisol, cortisol at certain levels triggers more substance P, and substance P drives inflammation that can worsen pain, skin flares, and gut symptoms.
Breaking this cycle doesn’t require eliminating stress entirely, but it does require interrupting the hormonal cascade. Practices that lower cortisol output, such as regular moderate exercise, adequate sleep, mindfulness meditation, and breathing techniques, can reduce the upstream signal that tells your cells to make more tachykinins. The effect isn’t instant the way a topical cream is, but it addresses one of the root triggers, particularly for people whose symptoms flare predictably with stress.
Vagus Nerve Stimulation
Stimulating the vagus nerve, the long nerve that connects your brainstem to your gut, heart, and other organs, has shown a strong suppressive effect on substance P. In research on peripheral inflammation, vagus nerve stimulation significantly reduced substance P gene expression in brain regions where the vagus nerve projects. The reduction was measurable and statistically significant, with substance P mRNA dropping from elevated inflammatory levels back toward baseline.
Vagus nerve stimulation is available as an implanted medical device for certain conditions, but non-invasive versions exist as well. Transcutaneous vagus nerve stimulators clip onto the ear or are held against the neck, and some are FDA-cleared for migraine and cluster headache. Cold water exposure, deep slow breathing with extended exhales, and gargling are all thought to activate the vagus nerve to varying degrees, though the evidence for these informal methods reducing tachykinins specifically is less direct.
Prescription Medications That Block Tachykinin Receptors
Rather than reducing the amount of tachykinin your body produces, another strategy is blocking the receptors those molecules bind to. Several FDA-approved drugs do exactly this.
NK1 receptor antagonists were the first class to reach the market. Aprepitant and its intravenous form fosaprepitant are approved to prevent nausea and vomiting from chemotherapy and surgery. Rolapitant, approved in 2015, is another NK1 blocker with an unusually long duration of action (a plasma half-life of 180 hours), meaning a single dose keeps working for days. These drugs prevent substance P from activating cells, which reduces the downstream inflammation and nausea signaling.
NK3 receptor antagonists are a newer class with a different target. In 2023, the FDA approved fezolinetant, the first selective NK3 receptor blocker, for moderate to severe hot flashes associated with menopause. It’s taken as a single 45 mg tablet daily. Then in October 2024, elinzanetant received FDA approval. Elinzanetant is notable because it blocks both NK1 and NK3 receptors simultaneously. In clinical trials, it reduced hot flash frequency by 56 to 58% at four weeks and 65 to 67% at twelve weeks, while also significantly improving sleep quality and overall quality of life. This dual-receptor approach provided larger reductions in symptoms compared to fezolinetant alone.
These medications are currently approved for specific conditions (chemotherapy-related nausea and menopausal hot flashes), not as general-purpose tachykinin reducers. But they demonstrate that blocking tachykinin receptors is a viable and effective pharmaceutical strategy, and the range of approved indications is expanding.
Diet and Lifestyle Factors
Several dietary and lifestyle factors influence tachykinin levels indirectly. Anti-inflammatory diets rich in omega-3 fatty acids may help because one of the downstream effects of tachykinin receptor activation is the generation of arachidonic acid, a precursor to inflammatory lipid molecules. Omega-3s compete with arachidonic acid in the same metabolic pathways, potentially dampening the inflammatory output even when tachykinins are present.
Regular aerobic exercise has been shown to modulate neuropeptide signaling broadly, including reducing circulating levels of inflammatory mediators. Sleep deprivation, on the other hand, is associated with elevated substance P and heightened pain sensitivity. Prioritizing consistent, adequate sleep (typically seven to nine hours) supports the body’s ability to regulate neuropeptide production rather than letting it spiral upward during periods of physiological stress.
Eating capsaicin-rich foods like chili peppers can have mild systemic effects over time, though the local depletion mechanism is much stronger with topical application. If you’re dealing with gut-related symptoms tied to tachykinin activity, note that capsaicin taken orally may initially worsen gut sensitivity before any depletion effect occurs, so topical use on the skin is generally more straightforward.
Choosing the Right Approach
The best strategy depends on where and why tachykinins are causing problems. For localized pain or skin-related inflammation, capsaicin cream applied consistently over two or more weeks is the most direct, over-the-counter option. For systemic issues tied to stress, addressing cortisol through sleep, exercise, and stress management techniques targets the upstream trigger. For specific medical conditions like chemotherapy nausea or menopausal hot flashes, prescription receptor blockers are the most effective tools available. And for people interested in a broader neuromodulatory approach, vagus nerve stimulation offers a way to suppress substance P production centrally.
These strategies aren’t mutually exclusive. Someone dealing with chronic pain and high stress, for example, could combine topical capsaicin on affected areas with a consistent stress-reduction practice and see compounding benefits from both approaches.