Mexidol (Emoxypine Succinate)

Mexidol (emoxypine succinate) is the succinic acid salt of emoxypine, 2-ethyl-6-methyl-3-hydroxypyridine, a synthetic 3-hydroxypyridine that a 2024 review describes as a derivative of vitamin B6. The same review lists emoxypine succinate as a registered drug in Russia and Ukraine under trade names including Mexidol, Mexicor and Armadin Long (Jędrejko et al., 2024), and a 2026 registry analysis found no registration for it in the United States, the United Kingdom or the European Union (Alexandrova et al., 2026).

PubChem CID 122298 lists the same CAS number, formula and weight and is the source of the aliases and structure; CID 114681 gives the emoxypine base figures.

Published work on Mexidol falls into five areas. Each summary below states the model used. Most of the literature is in Russian, and all trials summarized here are Russian-led.

Antioxidant and radical-scavenging chemistry

In three chemiluminescent oxidation systems, one of them a suspension of phospholipid liposomes, Mexidol, emoxypine hydrochloride and the related 3-hydroxypyridine proxipin bound ferrous iron and scavenged reactive oxygen species or luminol radicals, with Mexidol the most active (Klebanov et al., 2001). An independent density functional theory study from Vietnam and Australia predicted moderate hydroperoxyl radical scavenging and copper(II) chelation that blocks copper reduction by ascorbate, making copper binding its main predicted route against hydroxyl radicals (Hoa et al., 2022). Models: cell-free assays and computation.

Membranes and mitochondria

Young and old rats given water-soluble 2-ethyl-6-methyl-3-hydroxypyridine over a long course showed faster calcium transport into sarcoplasmic reticulum vesicles from heart and skeletal muscle (Kagan et al., 1986). In young and aging male rats, 20-day intraperitoneal courses at 40 and 100 mg/kg raised cortical levels of the succinate receptor SUCNR1 and of mitochondrial biogenesis markers such as PGC-1α, NRF1 and TFAM, more at the higher amount (Kirova et al., 2020). Models: rat muscle membranes and rat cortex.

Rodent ischemia and neuroprotection models

In rats with transient middle cerebral artery occlusion, Mexidol at 100 mg/kg intraperitoneally, from 6 hours after surgery and then daily for 6 days, reduced infarct volume by 30 percent, against 60 percent for the comparator GK-2, but did not reduce the limb placement deficit (Povarnina et al., 2017).

After photothrombosis in the rat prefrontal cortex, a 7-day course at 100 mg/kg, like nasal Semax, was associated with preserved neuron numbers and PGC-1α expression in the penumbra (Shakova et al., 2021). Outside Russia, an Indian group reported lower brain iron, oxidative stress and inflammatory markers and changed novel tank and Y-maze behavior in iron-overloaded zebrafish exposed to emoxypine succinate (Bagwe Parab and Kaur, 2025). Models: rats and zebrafish.

Anxiety-related behavior in rodents

In BALB/c and C57BL/6 mice tested in the open field, elevated plus maze and passive avoidance, Mexidol given once at 100 mg/kg intraperitoneally had a selective anxiolytic-like effect in BALB/c mice, a strain with a passive response to emotional stress, and no sedative effect in C57BL/6 mice (Kravtsova et al., 2004).

In rats given emoxypine hydrochloride or Mexidol three times, both produced anxiolytic-like and risk behavior in the elevated plus maze, close to amitriptyline; the hydrochloride, with no succinate, was stronger, and the authors linked the weaker Mexidol effect to its succinate (Volchegorskii et al., 2015). Models: mice and rats.

Clinical trials and the evidence base

The three multicenter trials below were randomized, double-blind and placebo-controlled, and were published in Russian. In EPICA, 150 adults aged 40 to 79 with hemispheric ischemic stroke received Mexidol or placebo, intravenously for 10 days and then orally for 8 weeks; the Mexidol group ended with lower modified Rankin (p=0.04) and NIHSS (p=0.035) scores, with no significant difference in side-effect frequency (Stakhovskaya et al., 2017).

In MEMO, 318 people aged 40 to 90 with chronic brain ischemia, in Russia and Uzbekistan, received a 14-day intravenous course and then 60 days of tablets, or placebo; the primary endpoint, change in MoCA score, favored Mexidol (p<0.000001), and adverse event profiles were reported as comparable (Fedin et al., 2021).

In MIR, 304 people with recent ischemic stroke at sites in Russia, Uzbekistan and Kazakhstan received a similar sequence or placebo alongside standard care. The Mexidol group showed larger changes in modified Rankin (p=0.003), NIHSS (p<0.001) and Rivermead Mobility Index (p=0.014) scores but only a trend on MoCA, and adverse events occurred in 23 percent of each group (Shamalov et al., 2025).

A 2023 meta-analysis pooled 11 stroke studies, all reported in Russian and only 2 of them randomized. It found lower NIHSS and modified Rankin scores than in comparison groups but marked heterogeneity, and said the evidence needs further examination (Voznyuk et al., 2023). PubMed indexes no randomized trial from outside Russia and other former Soviet states, so independent replication is limited. Models: human trials and a meta-analysis.