Palmitoylethanolamide (PEA) is an endogenous fatty acid amide that has been studied for its anti-inflammatory and analgesic properties. Its use for pain conditions, including neuropathic pain, has some scientific backing. For tension-type headaches specifically, the body of evidence is limited but emerging. A handful of small clinical studies and case reports suggest that PEA supplementation may reduce headache frequency and severity, likely due to its modulation of neuroinflammation and mast cell activity, as well as potential influence on pain signaling pathways. For example, a 2019 pilot study by Chirchiglia et al. found that PEA, when used as an adjunct, reduced headache intensity and frequency in patients with chronic migraine and tension-type headache; however, the study was small and open-label, limiting its generalizability. There are no large-scale, double-blind, placebo-controlled trials focused exclusively on tension-type headache and PEA. The mechanism is plausible—PEA may downregulate pro-inflammatory mediators involved in the pathophysiology of headaches—but robust clinical evidence is lacking. Reviews of PEA’s analgesic effects note its safety and potential for use in chronic pain, including headaches, but consistently call for further research. Thus, while there is preliminary scientific validation, the overall quality and amount of evidence for PEA in tension headache is still low to moderate.