Alpha Lipoic Acid: Benefits, Usage, and Side Effects

Alpha-lipoic acid is an antioxidant naturally produced by humans, animals, and plants. Although a healthy human body can produce enough alpha-lipoic acid, the production decreases significantly with age and illness. Thus, alpha-lipoic acid supplements have been gaining popularity.

These supplements have been proposed to offer potential antioxidant, anti-inflammatory, cognitive, cardiovascular, antimicrobial, anti-aging, anti-cancer, detoxifying, and neuroprotective properties.

The acid can be found naturally in some foods, taken as an oral supplement, or injected intravenously.

This article looks more in depth at what alpha-lipoic acid is, its potential benefits and side effects, and how to use it, as well as answering some frequently asked questions.

What is alpha-lipoic acid?

Alpha-lipoic acid is an organic compound and a biological antioxidant. It is important for numerous metabolic and enzymatic reactions and is usually found in the mitochondria of plant, animal, and human cells.

This compound exists in two similar yet distinct spatial arrangements: R and S, both of which have been proposed to offer slightly different health benefits. The naturally occurring alpa-lipoic acid found in food, mostly meat and vegetables, comes in the R form, whilst S isomer is made by synthetically. Supplements usually include both forms, aiming to target a diverse potential benefit profile.

Benefits of alpha-lipoic acid:

Alpha Lipoic Acid benefits

Alpha-lipoic acid has several potential health benefits, which are presented below. However, it is worth keeping in mind that most of the benefits still lack conclusive evidence. Thus, alpha-lipoic acid is not a medically recognized or prescribed supplement, nor is it able to treat any conditions.

Blood sugar control

Insulin is a hormone required for glucose uptake into the cells and blood sugar regulation. It is believed that alpha-lipoic acid supplementation may improve insulin sensitivity and reduce fasting blood sugar levels due to its natural involvement in metabolic and enzymatic functions.

Studies have shown that supplementing with alpha-lipoic acid improves glucose uptake in insulin-resistant mice, possibly by mediating one of the main signaling cascades involved in glucose uptake. However, the precise mechanisms are unclear. The compound may also improve blood sugar by counteracting insulin-inhibiting substances and protecting insulin-secreting cells from endotoxin damage.

Alpha-lipoic acid may also help increase insulin sensitivity, thereby contributing to blood sugar control. Despite showing promise in improving blood sugar levels and aiding insulin-resistant states in rodents, alpha-lipoic acid has not been thoroughly researched in humans and lacks supporting evidence.

Weight loss

Alpha-lipoic acid supplements have been proposed to aid weight loss, especially in obese individuals. Although the exact mechanisms are unclear, it may be due to increased energy expenditure, improved blood sugar and insulin control, and enhanced lipid metabolism. A meta-analysis of multiple studies has found that alpha-lipoic acid may offer small, short-term weight loss compared to placebo.

The mechanisms of action are underexplored, and there is a lack of conclusive evidence to state that taking additional alpha-lipoic acid leads to weight loss, as it is impacted by so many factors. The supplement may have some weight loss-promoting benefits; however, it is not a magic pill. Lifestyle and habit changes are required for sustainable and healthy weight loss and maintenance.


Alpha-lipoic acid is synthesized by the body to work as an antioxidant. It is thought that it may be able to lower inflammation by fighting free radicals, inhibiting certain pro-inflammatory signaling pathways, and suppressing inflammatory cytokines.

A study of patients with metabolic syndrome found that alpha-lipoic acid supplementation was associated with reduced inflammatory markers: IL-6, PAI-1, and 8-isoprostane.

Another study in patients with end-stage renal disease undergoing dialysis has found that alpha-lipoic acid did not lower major inflammatory markers like IL-8 and TNF-alpha. It shows that the anti-inflammatory effects are limited. The evidence remains inconclusive for alpha-lipoic acid to become a major anti-inflammatory supplement, requiring large-scale human trials.

Cardiovascular health

A systematic review of various studies concluded that alpha-lipoic acid can contribute to lower blood pressure in cases of hypertension. Both systolic and diastolic blood pressures saw significant reductions with alpha-lipoic acid supplementation.

The effects were stronger in individuals younger than 45 with some level of obesity (BMI 25-29.9) and less effective in diabetic patients. Obese patients might see more benefits due to the supplement’s aid in weight loss, as obesity is one of the main causes of hypertension.

Alpha-lipoic acid may lower blood pressure via various mechanisms, such as increasing nitric oxide and suppressing the renin-angiotensin system, leading to vasodilation and thus lowering blood pressure. Due to its antioxidant properties, alpha-lipoic acid may also be able to reduce the damage caused by reactive oxygen species and reduce atherosclerosis-causing blood lipids, providing a cardioprotective effect. However, scientific evidence is lacking to draw conclusions, highlighting the need for further research.

Antioxidant effect

Alpha-lipoic acid is a known antioxidant, playing a crucial role in protecting cells from oxidative damage caused by free radicals and reactive oxygen species. Free radicals and reactive oxygen species can accelerate cell aging and death, and thus, alpha-lipoic acid has been gaining popularity as a potential anti-aging supplement.

The antioxidant effects are also boosted by the compound's ability to regenerate other antioxidants, such as vitamins C and E, glutathione, and coenzyme Q10, increasing the cellular antioxidant defense system.

Alpha-lipoic acid has been suggested to protect against oxidative damage in the brain, heart, and kidneys, suggesting its potential to reduce oxidative stress and age-related diseases. However, most studies have been done in vitro or in animals, with few in human trials, making it hard to draw sound conclusions.

Skin benefits

Alpha-lipoic acid may have some potential skin-improving benefits, such as reducing wrinkles, skin damage, exfoliation, and inflammation. This is believed to be mostly mediated via its action as an antioxidant. Alpha-lipoic acid is included in many skin products, so you can easily incorporate it into your routine without the need for additional supplementation.

Side effects of alpha-lipoic acid

Alpha-lipoic is safe for most individuals. However, there are some reports that supplements can cause the following side effects:

  • Gastrointestinal symptoms: nausea, vomiting or diarrhea
  • Skin rashes
  • Allergic reactions
  • Urological system complications
  • Nervous system complications

It has been observed that side effects tend to worsen with higher doses and prolonged use. If you start experiencing side effects, you should stop using the supplement immediately. The bioavailability of alpha-lipoic acid is only around 30%, making it very hard to determine the required doses, the effectiveness of the supplement as well as its safety.

Possible safety concerns and interactions with other supplements or medication

Alpha-lipoic acid has been proposed to interfere with the immune system and lead to severe hypoglycemia in some genetically predisposed individuals due to interactions with insulin that are yet unclear. It also has the potential to lower blood sugar levels, which may be risky for individuals with diabetes or those taking blood sugar-lowering medications. Therefore, alpha-lipoic acid supplements should not be combined with antidiabetic drugs or other substances that may affect blood glucose levels.

It may also negatively interact with chemotherapy drugs, thyroid medications, and medications that contain iron. It is essential to consult with a healthcare professional before starting alpha-lipoic acid supplementation, especially for individuals with underlying health conditions or those taking medications.

Who shouldn’t use alpha-lipoic acid?

The following groups should thoroughly consult their healthcare provider or avoid taking alpa-lipoic acid supplements altogether:

Pregnant or breastfeeding womenIndividuals with thyroid disordersIndividuals with thiamine (B1) deficiencyIndividuals scheduled for surgery
Consult, safety is not establishedConsultAvoidAvoid or discontinue use

Foods rich in alpha-lipoic acid:

Alpha-lipoic acid is a supplement that is not regulated by the FDA. Hence, it is hard to determine the exact dose, efficacy and quality of the supplement, requiring thorough research before using supplements. To stay on the safer side, it might be worth increasing the intake of food rich in alpha-lipoic acid. Here is a list of foods naturally high in alpha-lipoic acid:

  • Organ meats (liver, kidneys)
  • Spinach
  • Broccoli
  • Brussels sprouts
  • Tomatoes
  • Peas
  • Rice bran
  • Brewer's yeast
  • Potatoes
  • Carrots

How to take alpha-lipoic acid?

Alpha-lipoic acid is available as a supplement in tablet or capsule form. Due to its potential gastrointestinal side effects, some people might feel better taking it with meals. You should always follow the manufacturer's recommendations and consult a healthcare professional before using the product.

How much is safe to take according to available scientific evidence?

The exact dose of alpha-lipoic acid that is safe to take varies based on individual factors, such as age, health status, and tolerance. However, research studies typically use doses of up to 6001800 mg per day. You should always start with a lower dose, consult a healthcare provider, and keep a close eye on the potential side effects.

When to take?

Alpha-lipoic acid supplements can be taken at any time of the day, depending on individual preference and convenience. Some people report less gastrointestinal discomfort when taking the supplement with breakfast, while others find it easier to take separately. Overall, consistency matters more than the precise time of day for taking the supplement.

Dosage for neuropathy

In clinical studies of neuropathy, alpha-lipoic acid was administered intravenously in a clinical setting in doses of 300–600 mg/day for 2–4 weeks. However, as individual responses may vary, thus it is essential to consult with a healthcare professional for personalized recommendations based on your individual condition.

What’s the difference between alpha-lipoic acid and R-lipoic acid?

Alpha-lipoic and R-lipoic acids are similar compounds with different spatial structures. In supplements, Alpha-lipoic acid is a mixture of R and S isomers, while R-lipoic acid contains only the R enantiomer. R-lipoic acid is considered more biologically active and the naturally occurring form and is believed to be more potent and readily absorbed by the body.

Alpha-lipoic acid theoretically looks promising as a dietary supplement with various health benefits. However, its efficacy and safety are yet to be determined, and further research is needed to establish conclusive evidence. Consulting a healthcare professional before starting supplementation is essential to ensure its appropriate use and minimal side effects.


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