Bulimia

Acetyl-L-carnitine (ALCAR) counters mitochondrial injury in cochlear hair cells caused by noise exposure. Combined with NAC in animal studies, ALCAR significantly reduced permanent hearing threshold shifts and hair cell loss after acoustic trauma. It has also been studied for age-related auditory decline, with mechanistic evidence supporting its role in cochlear mitochondrial repair.

Alpha-lipoic acid (ALA) is a mitochondrial antioxidant that crosses the blood-brain barrier and protects cochlear hair cells from noise-induced and age-related oxidative damage. Animal studies confirm ALA protects against cisplatin-induced and noise-induced hearing loss. A preliminary human study evaluated ALA's effects on temporary threshold shift (TTS) in volunteers exposed to noise, showing otoprotective trends.

Coenzyme Q10 (CoQ10) supports mitochondrial energy production and acts as a powerful antioxidant in cochlear cells. A 2025 double-blind RCT (n=50) found 100 mg/day of CoQ10 significantly decreased tinnitus disability and loudness in presbycusis patients over 6 weeks. A 2007 clinical trial showed benefit for tinnitus patients with low CoQ10 blood levels. A 2026 systematic scoping review identified 14 studies linking CoQ10 to hearing outcomes.

Fisetin is a flavonoid antioxidant that has demonstrated otoprotective properties in animal models, protecting cochlear hair cells from cisplatin-induced and noise-induced damage. It activates SIRT1 and reduces oxidative stress in the cochlea. Fisetin has been studied specifically for sensorineural hearing loss in preclinical research.

Ginkgo biloba (standardized extract EGb 761) is the most-studied herbal supplement for tinnitus and hearing loss. It is believed to improve inner-ear and cerebral blood circulation and protect against free radicals. European and American otolaryngology guidelines have recommended it for reducing tinnitus annoyance. Evidence from randomized controlled trials is mixed but a systematic review of five RCTs concluded standardized extract is an evidence-based treatment option for tinnitus.

Glutathione (GSH) is the primary endogenous antioxidant in cochlear hair cells. Its depletion is a key mechanism in noise-induced and cisplatin-induced hearing loss. Animal studies confirm that exogenous glutathione limits noise-induced hearing loss, and NAC (a GSH precursor) has been the primary clinical proxy. Glutathione itself has been evaluated as an otoprotective agent.

Luteolin is a flavone with otoprotective properties demonstrated in animal studies, protecting cochlear hair cells from noise-induced and cisplatin-induced damage via antioxidant and anti-inflammatory mechanisms. It is included in the ConsumerLab-referenced Advanced Hearing Formula (25 mg per serving) alongside other evidence-based hearing ingredients.

Magnesium has been studied in both noise-induced hearing loss (NIHL) and tinnitus. Israeli military studies showed that soldiers taking magnesium before noise exposure experienced significantly less permanent hearing loss than controls. Magnesium's vasodilatory and neuroprotective effects are believed to protect cochlear hair cells during acoustic trauma. It also shows some evidence for reducing tinnitus severity.

Melatonin is a potent antioxidant hormone studied for prevention of age-related hearing loss (presbycusis) and noise-induced ototoxicity. Animal studies in C57BL/6J mice (12-month intervention) confirmed melatonin prevented cochlear hair cell degeneration. Melatonin has been used in combination with CoQ10 in clinical pilot trials showing protection against cisplatin-induced hearing damage.

Methylcobalamin is the bioactive, neurologically active form of vitamin B12, specifically recommended for hearing health applications over cyanocobalamin. Low serum vitamin B12 is significantly associated with age-related hearing loss and tinnitus. B12 deficiency causes degeneration of cochlear nerve neurons. Methylcobalamin specifically appears in clinical hearing supplement formulas referenced by ConsumerLab and NIH-associated practitioners.

N-acetyl cysteine (NAC) is a precursor to glutathione, the main cellular antioxidant in cochlear hair cells. Multiple animal studies demonstrate NAC significantly reduces noise-induced cochlear hair cell loss and permanent threshold shifts. A ScienceDirect 2006 study showed NAC significantly reduced permanent threshold shifts and hair cell loss in animals when given 1–4 hours post-noise exposure. Human results are mixed but mechanistically well supported.

Nicotinamide riboside (NR) is a NAD+ precursor that protects cochlear nerve synapses from noise-induced damage. Weill Cornell research (Cell Metabolism, 2014) showed NR prevented synaptic degeneration and both short- and long-term hearing loss in noise-exposed mice. Multiple subsequent animal studies confirmed NR protects hair cell ribbon synapses, cochlear hair cells, and auditory neurons from noise and age-related damage.

Multiple large prospective cohort studies link higher dietary omega-3 intake and blood DHA levels to significantly lower rates of age-related hearing loss. A Nurses' Health Study follow-up of 65,215 women over 18 years found women eating two or more fish servings per week had a 20% lower hearing loss risk. UK Biobank data (n>100,000) showed top-quintile DHA blood levels were 16% less likely to report hearing difficulty.

Pine bark extract (Pycnogenol) improves cochlear blood flow and microcirculation, and has been evaluated in small clinical trials for tinnitus and sudden sensorineural hearing loss. It enhances endothelial nitric oxide production, improving inner-ear vasculature. A controlled study found pine bark extract improved tinnitus and hearing in patients with Meniere's disease.

Quercetin is a flavonoid antioxidant with demonstrated protective effects against cisplatin-induced and noise-induced cochlear damage in animal models. It inhibits NF-κB inflammatory signaling in cochlear hair cells and is included in evidence-referenced hearing health formulations. Quercetin also has vasodilatory effects that may support cochlear blood flow.

Steamed Rehmannia root has traditional use in TCM for inner ear diseases including tinnitus and hearing loss. In vitro research (J Ethnopharmacol, 2006) demonstrated that Rehmannia extract protected auditory hair cells (HEI-OC1) from cisplatin-induced ototoxicity in a dose-dependent manner via free radical scavenging. The herb is listed in a Chinese integrative medicine review as a candidate for acquired nerve deafness treatment.

Resveratrol activates SIRT1 in the cochlea, reducing oxidative stress and promoting recovery from noise-induced hearing loss. PubMed studies in C57BL/6 mice show long-term resveratrol supplementation resulted in better hearing recovery and less hair cell loss after intense noise exposure. Resveratrol also has protective effects against cisplatin- and aminoglycoside-induced hearing loss.

Selenium is an antioxidant mineral whose deficiency is linked to increased hearing loss risk. Selenium, along with zinc, has been shown to exert a clinically favorable effect on tinnitus intensity in patients with low levels of these minerals. A 2019 PubMed review identified selenium deficiency as a risk factor for hearing loss.

Taurine is distributed throughout the central and peripheral auditory system and plays an important role in the anatomical and functional development of the auditory system. Animal studies demonstrate that taurine protects cochlear hair cells from ototoxic damage and promotes cochlear neural stem cell proliferation.

Vitamin A deficiency is associated with increased hearing loss risk, and vitamin A combined with vitamins C, E, and magnesium has demonstrated otoprotective effects in both animal models and human research. A 2020 animal study confirmed that oral antioxidant vitamins A, C, E, and magnesium reduced auditory threshold shifts after noise-induced hearing loss by promoting outer hair cell survival.

Vitamin B12 deficiency is associated with age-related hearing loss and tinnitus. Low serum B12 correlates with higher audiometric thresholds in the elderly and with tinnitus in noise-exposed workers. Studies show women with impaired hearing had 48% lower serum B12 than women with normal hearing. Supplementation in deficient patients has shown benefit for tinnitus symptoms.

Niacin (vitamin B3) promotes cochlear blood flow via vasodilation and is a NAD+ precursor. Research from Weill Cornell Medical College showed that its derivative nicotinamide riboside prevents noise-induced damage to cochlear nerve synapses. Niacin has historically been used for sudden hearing loss and tinnitus via vasodilatory effects. A 2024 Stanford review confirmed vitamin B3 protects cochlear structures.

Vitamin B6 works alongside folate and B12 to regulate homocysteine metabolism, which when dysregulated contributes to cochlear vascular damage and hearing loss. B6 is frequently included in tinnitus supplement formulas with supporting evidence from observational studies. It supports auditory nerve function and is found in clinical hearing-supplement trials.

Folate (vitamin B9) reduces homocysteine levels, which when elevated impair cochlear blood flow and contribute to sensorineural hearing loss. Multiple population studies, including NHANES data, link low folate status to higher rates of hearing loss. Women with hearing impairment had 43% lower red-cell folate than those with normal hearing in a landmark PubMed study.

Methylfolate (5-MTHF) is the bioactive form of folate and shares the same hearing-health evidence as folic acid, particularly for homocysteine-mediated cochlear damage. Low folate status is significantly associated with age-related hearing loss, with optimal folate levels correlating with lower audiometric thresholds. A NHANES cross-sectional study confirmed this association.

Vitamin C is an antioxidant studied for prevention of noise-induced hearing loss. Animal studies show vitamin C protects cochlear cells from acoustic trauma. Combined with vitamins A, E, and magnesium, it demonstrated otoprotective effects in multiple animal models and epidemiological studies. Some large epidemiological data suggest protective associations.

Vitamin D deficiency is associated with increased tinnitus loudness and higher risk of sensorineural hearing loss. Clinical trials have shown that correcting vitamin D deficiency can reduce tinnitus severity. Studies evaluating vitamin D supplementation for sudden hearing loss have shown modest benefit at moderate doses. Vitamin D receptors are present in cochlear cells.

Vitamin D3 (cholecalciferol) is the preferred form of vitamin D for supplementation and shares the same hearing-health evidence base as vitamin D generally. Deficiency correlates with higher hearing loss risk, increased tinnitus loudness, and worse outcomes in sudden SNHL. Correcting deficiency with D3 has shown clinical benefit for tinnitus in RCTs.

Vitamin E (tocopherol) is a fat-soluble antioxidant studied for otoprotection from noise and aging. Animal and epidemiological studies show it protects cochlear hair cells from oxidative damage. Combined with vitamins A, C, and magnesium, it has demonstrated otoprotective effects in animal models of noise-induced hearing loss.

Zinc deficiency is associated with tinnitus and increased hearing loss risk. Zinc is essential for immune function and inner-ear tissue maintenance, and zinc supplementation has been studied in tinnitus patients with low serum zinc levels showing some clinical improvement. Multiple reviews identify zinc as having a clinically favorable effect on tinnitus intensity, particularly in zinc-deficient patients.

Rehmannia features in TCM formulas specifically indicated for tinnitus and hearing loss associated with Kidney Yin deficiency. The Restorative Medicine monograph lists it for 'hearing damage (gentamicin-induced)' and there is some practitioner-level support for its use in inner ear disease, but controlled human trial data are lacking.