Glycine propionyl-L-carnitine (GPLC) is a propionyl ester of carnitine that has been investigated for its potential benefits in circulatory and nerve health, including peripheral neuropathy. The rationale for its use in peripheral neuropathy is based on its ability to improve endothelial function, enhance nitric oxide production, and support mitochondrial energy metabolism, which may help in conditions involving microvascular dysfunction and nerve ischemia. Several small clinical studies have looked at related forms, especially propionyl-L-carnitine (PLC), rather than GPLC specifically, for peripheral neuropathy, particularly in diabetic and ischemic etiologies.

For example, randomized controlled trials (RCTs) have shown that PLC can improve neuropathic symptoms and nerve conduction in patients with diabetic neuropathy and peripheral arterial disease. However, direct evidence for GPLC itself is sparse, with most data extrapolated from studies on PLC or L-carnitine. Mechanistic studies suggest potential benefits via improved blood flow and antioxidant effects, but large, high-quality RCTs specifically examining GPLC in peripheral neuropathy are lacking.

In summary, while there is some scientific rationale and preliminary evidence (mainly for PLC, not GPLC specifically), the overall quality and quantity of evidence supporting GPLC for peripheral neuropathy is limited. Thus, the evidence rating is 2/5, reflecting early clinical data but a need for more robust, targeted research.