Substance P in Fibromyalgia

High Levels Lead to Excess Pain

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Substance P is a small peptide that's released when your nervous system is stimulated. It's involved in regulation of the pain threshold (the point at which sensation is perceived as pain.) Increased levels of substance P can make nerves more sensitive to pain and heighten your awareness of pain.

Research suggests that some people with fibromyalgia may have elevated levels of substance P.

This is believed to be one of several abnormalities in the nervous system that work together to increase pain sensitivity in the condition, a process that's often referred to as "turning up the volume" on pain.

Substance P often functions as a neurotransmitter, which means that it communicates signals from one brain cell to another. It's one of several neurotransmitters believed to be dysregulated in fibromyalgia.

An example of heightened pain sensitivity, which could involve a higher than normal level of substance P, is a common fibromyalgia symptom called allodynia. Allodynia is the medical term for pain caused by something that normally wouldn't cause pain. In fibromyalgia, a common source of allodynia is light pressure from clothing. The pain can come from a waistband, even if it's not tight; a bra strap; or the elastic in your socks. Most people wouldn't experience pain from these things, but people with fibromyalgia do.

(See Cut Clothing Pain with Fibromyalgia.)


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Bokarewa MI, et al. Mediators of inflammation. 2014;2014:627041. Smoking is associated with reduced leptin and neuropeptide Y levels and higher pain experience in patients with fibromyalgia.

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