What Is Alpha-Lipoic Acid?

Alpha-lipoic acid (ALA) is a naturally-occurring fatty acid made by your body. Its primary role is to convert blood sugar (glucose) into energy using oxygen, a process referred to as aerobic metabolism. ALA is also an antioxidant, meaning it neutralizes harmful compounds called free radicals that damage cells at the genetic level.

Your body makes its own ALA, but it is also available from certain foods and as a supplement. Though ALA supplements are marketed for many health conditions, there is little evidence to support their use.

This article reviews the potential uses of ALA and also covers side effects and possible interactions.

Uses of Alpha-Lipoic Acid

Supplement use should be individualized and vetted by a healthcare provider. No supplement is intended to treat, cure, or prevent disease.

Many integrative medicine healthcare providers contend that ALA can prevent or manage several health conditions, including alcoholic liver disease, HIV, Alzheimer's disease, bipolar disorder, high blood pressure, rheumatoid arthritis, schizophrenia, erectile dysfunction, and more. To date, there is little evidence to support any of these claims.

Much of the research involving ALA has been centered on the management of diabetes and nerve pain. The following conditions are some of the potential uses for ALA.

Diabetes

ALA may aid in the control of glucose by speeding up the metabolism of blood sugar. This could potentially help manage diabetes, a disease characterized by high blood glucose levels.

A 2018 review of 20 randomized controlled trials looked at ALA use in people with metabolic disorders, including type 2 diabetes. Results showed ALA supplementation lowered fasting blood glucose, insulin concentration, insulin resistance, and hemoglobin A1C levels. Your hemoglobin A1C level shows your average blood sugar over the past three months.

A review published in 2019 suggested ALA reduced fasting blood glucose and A1C levels. However, a more recent systematic review found that ALA supplementation reduced insulin and insulin resistance but did not reduce A1C levels.

If you have diabetes and are considering ALA supplementation, ask a healthcare provider if it would be appropriate for your needs.

Nerve Pain

Neuropathic pain is the medical term used to describe the pain, numbness, and abnormal sensations caused by nerve damage. The damage is often caused by oxidative stress placed on the nerves by chronic diseases like:

• Diabetes
• HIV
• Kidney failure
• Lyme disease
• Shingles
• Thyroid disease

A clinical trial published in 2021 found that people with pain from unknown causes reported less severe pain scores when they took between 400 milligrams and 800 milligrams of an oral ALA supplement compared to those who took a placebo.

A review of studies from the Netherlands showed that a daily 600 milligrams intravenous dose of ALA given over three weeks reduced neuropathic pain. Another review found that daily intravenous doses of 300 milligrams to 600 milligrams for two to four weeks were safe and improved neuropathy symptoms. However, since the doses were provided intravenously, the results can't be applied to taking oral supplements.

Weight Loss

ALA's ability to enhance calorie burning and promote weight loss has been exaggerated by many diet gurus and supplement manufacturers. In addition, much of the research on supplementing ALA for weight loss is preliminary and does not provide firm conclusions.

A 2017 review of studies from Yale University found that ALA supplements, ranging in doses from 300 milligrams to 1,800 milligrams daily, helped prompt an average weight loss of 2.8 pounds compared to a placebo. Another review of studies published in 2018 similarly found that ALA resulted in more weight loss compared to placebo. However, the average weight loss was only 1.5 pounds.

An additional meta-analysis published in 2020 found that treatment with ALA significantly reduced body mass index and reduced weight by about 5 pounds as compared to a placebo.

While these three systematic reviews offer some promising evidence, the study methods varied greatly among the individual studies. As a result, it's difficult to draw firm conclusions from them.

The reviews found a statistically significant difference in the amount of weight lost between treatment and placebo groups.

Heart Disease

ALA has long been believed to influence weight and health by altering the lipid (fat) composition in the blood. This includes increasing "good" high-density lipoprotein (HDL) cholesterol while lowering "bad" low-density lipoprotein (LDL) cholesterol and triglycerides. However, recent research suggests this may not be so.

One study showed that 180 Korean adults who were given 1,200 milligrams to 1,800 milligrams of ALA lost 21% more weight than the placebo group after 20 weeks. However, they experienced no improvements in total cholesterol, LDL, HDL, or triglycerides. In fact, higher doses of ALA were connected to increases in total cholesterol and LDL in study participants. A 2019 study also found no improvements in serum lipids with ALA.

However, there is some evidence that ALA can reduce markers of inflammation, such as C-reactive protein, interleukin-6, and tumor necrosis factor-alpha (which promotes insulin resistance and is associated with obesity-induced, type 2 diabetes). High levels of C-reactive protein are considered a risk factor for heart disease.

A 2019 review found a significant reduction in these three markers with supplementation of ALA. In addition, another study published in 2020 found that 600 milligrams of ALA given orally for four months significantly reduced these same markers.

Primary Mitochondrial Disorders

ALA supplementation has been recommended in people with primary mitochondrial disorders, or PMDs. PMDs are rare genetic disorders that occur due to errors in the function of the mitochondria, limiting the body's ability to make energy within cells.

There is very little evidence to support the use of ALA in this population. Most of the evidence is based on case reports simply because the disorders are so rare. People with PMDs should be monitored by a team of specialists who focus on these complex metabolic disorders.

ALA deficiency is extremely rare. Generally, healthy people can produce all the ALA the body needs.

What Are the Side Effects of Alpha-Lipoic Acid?

ALA is generally considered safe when taken as an oral supplement or used as a topical (cream) ointment. It has also been found to be "safe, effective, and stable" when given intravenously, according to one Food and Drug Administration (FDA) report.

The same report says there does "not appear to be significant adverse effects associated with" alpha-lipoic acid. However, some people may experience some side effects, including:

• Low blood sugar
• Nausea
• Rash (when using an ALA cream or ointment)
• Vomiting

Since ALA is an acid, it may contribute to reflux. Eating a small snack (like graham or saltine crackers) with dosage can help ease heartburn or reflux.

Precautions

Supplementation of ALA in children has not been carefully studied. Therefore, it is not recommended for children.

Like many other supplements, ALA is not recommended for people who are pregnant, breastfeeding, or chestfeeding. Not enough research has been done to understand ALA's effects in these groups.

Dosage: How Much Alpha-Lipoic Acid Should I Take?

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.

While ALA is considered safe, there are no guidelines directing its use. Most oral supplements are sold in capsule or tablet formulations ranging from 100 milligrams to 600 milligrams. A dose of 600 milligrams to 1,200 milligrams daily appears the most common in studies. This is typically divided into three equal doses each day.

These numbers are meant only to give you an idea of a possible daily dosage. It's never wise to follow an arbitrary number or someone else's dosage plan. No two people are alike, and someone else may be dealing with circumstances you are unaware of.

Like most nutritional supplements, ALA should be stored in a cool, dry place.

What Happens If I Take Too Much Alpha-Lipoic Acid?

Since ALA is not an essential nutrient, there is no recommended amount to get in your diet or through supplements. There also is no set upper intake limit. If you take too much ALA, you may experience some of the side effects discussed above, but they tend to resolve when the supplement is stopped.

Otherwise, one reported case of a 70-year-old woman who experienced multiple organ failures from too much ALA. But this was partially caused by a prescribing error. Accidental exposure to ALA caused one toddler to experience convulsions. In general, it is important to keep all medications and supplements out of the reach of children and pets to avoid accidental ingestion.

Additionally, a 22-year-old woman was admitted to an emergency department after an intentional overdose of ALA. She presented with tachycardia or a rapid heartbeat, altered mental state, metabolic acidosis, and an abnormal electrocardiogram (EKG). She was treated and discharged from the hospital three days later. 

In nonhuman animal studies, high levels of ALA were reported to cause changes in liver function, alteration in liver enzymes, apathy, and confusion. While we can’t conclude toxicity using nonhuman animal studies alone, it may be worth considering when frequently taking high doses of ALA.

Interactions

It is essential to carefully read the ingredient list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Review this supplement label with a healthcare provider to discuss any potential interactions with foods, other supplements, and medications.

ALA supplements may:

• Affect thyroid function and treatment. If you have thyroid disease or are taking thyroid medications, talk to a healthcare provider before taking ALA.
• Interfere with the success of chemotherapy treatment. Discuss any nutritional supplementation with an oncologist if you are undergoing cancer treatment.
• Reduce blood glucose levels if you are also taking glucose-lowering medications. If you have diabetes, discuss whether ALA supplements are appropriate for you with a healthcare provider. If you take this supplement, monitor your blood glucose levels closely.
• Slow blood clotting and increase the risk of bleeding. A healthcare provider should monitor you closely if you are also on blood thinners. Discuss with a healthcare provider whether ALA supplements are appropriate for you.

Sources of Alpha-Lipoic Acid & What To Look For

The food you eat will always be your best source of nutrients. If you have a healthy appreciation for vegetables, you may be able to get plenty of ALA from your diet. ALA can be found in:

• Beets
• Broccoli
• Brussels sprouts
• Carrots
• Peas
• Potatoes
• Red meat
• Spinach
• Tomatoes
• Yams

Alpha-Lipoic Acid Supplements

Dietary supplements are not regulated in the United States. This means the FDA does not approve them for safety and effectiveness before they are marketed. When possible, choose a supplement that has been extensively tested by a trustworthy third-party, such as ConsumerLab.com, NSF International, and U.S. Pharmacopeia (USP).

But just because a supplement has been through third-party testing doesn't mean it's safe—or effective. Always seek the advice of a healthcare provider before taking a new supplement.

Summary

Alpha-lipoic acid is a fatty acid found naturally inside every cell of the human body. Its primary role is to convert blood sugar (glucose) into energy using oxygen. Many people use it to help with diabetes, nerve pain, weight loss, heart disease, and primary mitochondrial disorders.

Side effects of using ALA appear mild and, when they're not, seem to be caused by overindulging. Like other supplements, ALA is capable of interacting with other medications. So it's crucial that a healthcare provider understands your full health picture before offering a verdict on whether you can safely use ALA.

If the supplement aisle at your favorite grocery store seems to be getting more crowded, the good news is that you have more product choices. Then again, the not-so-good news is that you have more choices. Sometimes, more choices can breed confusion.

Supplements aren't like prescription medication, so you shouldn't expect quick results. If you notice any effect from a supplement, it's likely to be subtle, and it may take time. And while supplements may support health, they don't treat or cure disease or deliver miracles in the form of a tablet. If a supplement makes a life-saving claim that sounds too good to be true, it most likely is.