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R-Lipoic Acid vs Alpha Lipoic Acid
R-lipoic acid vs alpha lipoic acid is a question of form. Lipoic acid exists as two mirror-image forms, R and S, and the plain name alpha lipoic acid does not say which one is in the capsule. The Synaptril label prints only "Alpha Lipoic Acid", so the form is not stated.
Written by the Synaptril label deskUpdated · 4 min read
Is R-lipoic acid the same as alpha lipoic acid?
R-lipoic acid is one form of alpha lipoic acid, not a different compound. The molecule comes as two mirror images, called R and S.
A label that says only "alpha lipoic acid" does not tell you which form, or what mix of the two, is inside. Our sources do not settle which is better, so we claim nothing.
What does the Synaptril label say?
The label says "Alpha Lipoic Acid", with no R, no S and no amount. It is line 2 of 6 in a 575 mg proprietary blend.
That is normal for a blend, which only has to show a total weight and the order of ingredients (21 CFR 101.36, Supplement Facts).
| Question | Synaptril label |
|---|---|
| Which form, R or S? | Not stated |
| Amount per capsule? | Not printed; at most about 175 mg by our math |
| Place in the blend? | Second of six |
Does the form change the evidence?
The studies we cite do not split results by form. Human trials used about 200 to 1,800 mg a day of alpha lipoic acid (Linus Pauling Institute, Lipoic Acid), and Cochrane found no qualifying trials in dementia (Cochrane, Alpha lipoic acid for dementia).
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See packsHow much lipoic acid fits in one Synaptril capsule?
One Synaptril capsule holds at most about 175 mg of alpha lipoic acid, whichever form it is, and the true amount may be far smaller.
Magnesium glycinate is about 14% magnesium (GlobalRPH, Magnesium Glycinate). Reaching 80 mg of magnesium takes about 567 mg of it, which leaves about 8 mg of the 575 mg blend for the other five lines. Even a richer 20% grade needs 400 mg and leaves 175 mg for all five.
The bar below shows the split. Form is a second unknown on top of this first one.
What should you check on any ALA label?
Check three things: the form named, the amount per capsule and whether the amount sits in a blend. Synaptril names none of the first two.
Read the alpha lipoic acid profile and the Synaptril supplement facts. Our post on alpha lipoic acid and blood sugar covers the main caution.
FAQ01
Synaptril questions people ask
Is R-lipoic acid better than regular alpha lipoic acid?
We cannot say. None of the sources we cite compares the forms, so any claim of better results would go beyond them. What is clear is that the Synaptril label does not name its form.
Why do supplement labels rarely state R or S?
Rules do not require it. A plain ingredient name is enough, and a proprietary blend needs only a total weight and an order of ingredients. If form matters to you, ask the seller before buying.
What does the R in R-lipoic acid mean?
R names one of the two mirror-image forms of lipoic acid, the other being S. They are two shapes of one compound, and the Synaptril label names neither.
How can I tell which form of lipoic acid a product uses?
Look for R or S in the ingredient name. A plain "alpha lipoic acid" does not state the form. If it matters to you, ask the seller, for Synaptril the order desk at [email protected], before you buy.
Who wrote this02
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . Learn about our editorial standards and how we check reviews. This website is run by a U.S. retail partner of Synaptril, not by the manufacturer or the distributor. We make money when you buy through our order links.
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