Therapeutic applications of alpha-lipoic acid: A review of clinical and preclinical evidence (1998–2024)

Alpha-lipoic acid (ALA) is an endogenously synthesized compound known for its potent antioxidant and anti-inflammatory properties, with growing interest for its therapeutic potential in conditions linked to oxidative stress. This review aims to critically evaluate the current scientific evidence on the therapeutic use of ALA, focusing on the injectable route. A total of 48 studies published between 1998 and 2024 were included, comprising both clinical and preclinical models in which ALA was administered alone or in combination with other bioactive compounds. While oral administration was the most common, injectable ALA demonstrated superior bioavailability and efficacy in specific experimental settings, particularly in animal models. The findings highlight ALA's benefits in metabolic, neurodegenerative, musculoskeletal, and gestational conditions and oxidative damage prevention. However, gaps in the literature remain, notably the lack of clinical trials using injectable formulations and studies in vulnerable populations. In conclusion, although injectable ALA are shows therapeutic promise, further standardized and controlled clinical trials are needed to confirm its safety and efficacy in humans. • ALA shows potent antioxidant action and therapeutic effects in chronic diseases. • Injectable ALA provides greater bioavailability and rapid therapeutic response. • ALA supplementation improves pain, inflammation, and mitochondrial function. • ALA combined with vitamins and minerals enhances therapeutic effectiveness. • Human studies indicate that ALA is safe, although long-term trials are still lacking.