Two forms of alpha-lipoic acid
| Form | What it is |
|---|---|
| Alpha-lipoic acid (ALA) | The standard form, a mix of the R and S mirror-image molecules. The label gives the weight of alpha-lipoic acid. |
| R-alpha-lipoic acid, sodium salt (Na-RALA) | Only the R mirror image, which is the one made naturally in the body, bound to sodium for stability. The label gives the weight of the sodium salt. |
Because the forms are different, 300 mg of standard ALA and 50 mg of Na-RALA cannot be compared as plain numbers. Read the form first and the milligrams second.
Alpha-lipoic acid products compared
| Product | Form | Daily dose | Amount | Capsule | Pack lasts |
|---|---|---|---|---|---|
| Swanson Alpha-Lipoic Acid 300 mg, 60 capsules | standard ALA | 1 capsule | 300 mg | gelatin | 60 days |
| Swanson R-Fraction Alpha-Lipoic Acid 50 mg, 60 capsules | R-ALA Bio-Enhanced Na-RALA | 1 capsule | 50 mg | gelatin | 60 days |
Both packs last 60 days at one capsule a day. The price per day on each card is therefore the pack price divided by 60.
Health claims
The EU register of authorised health claims has no statement for alpha-lipoic acid. Under Regulation (EC) No 1924/2006 we therefore do not describe effects on blood sugar, nerves, ageing or anything else, and we ask you to treat any page that does with caution. Our product pages give the form, the dose and the manufacturer warnings.
Where it occurs
Alpha-lipoic acid is made in small amounts by the body and is also found in foods such as red meat and some vegetables. A capsule delivers a fixed measured amount, which is much more than a normal diet provides, so it is a supplement and not a food replacement.
Before you buy
Both labels say the product is not recommended for pregnant and breastfeeding women. The 300 mg label also says adults only and that people who take prescription medicines should consult a doctor first. This matters because alpha-lipoic acid is taken by some people alongside other treatments. Do not exceed one capsule a day. For related categories see coenzyme Q10, B vitamins and magnesium.
How to choose
Start from the form, because that decides how to read the dose. The standard capsule states a larger number of milligrams, while the R-form states a smaller one for a different molecule. Neither number tells you which product is better. Compare the form, the capsule and the price per day, and keep to one capsule a day as the labels say.
Questions
Which form should I choose?
They are different molecules, so milligrams are not comparable. Choose by form, dose and price per day.
When do I take it?
Swanson gives no set time on these labels: one capsule a day. Follow the pack.
Is it vegan?
The capsule shells of both products are gelatin, so they are not vegan.
Can I take it with medicines?
Swanson advises consulting a doctor first if you take prescription medicines. Ask a doctor or pharmacist before you start.
Sources
- Regulation (EC) No 1924/2006 (nutrition and health claims)
- Regulation (EU) No 432/2012 (permitted health claims)
- EFSA: Health claims
Content reviewed by Inese Kalniņa, dietitian.
2026-07-02