Ranked by how strong the human evidence is — best supported first.
Best supportedBody compositionNot enough evidence· no source yetThen, in order
Synthetic amphetamine-like stimulants sold in pre-workout and weight-loss products, often under botanical names such as geranium or Aconitum kusnezoffii. Neither occurs meaningfully in the plants they are attributed to.
DMAA is the clearest case in the supplement world of a substance that regulators removed and the market kept selling. It was a nasal decongestant drug decades ago, reappeared as a supplement ingredient marketed as a geranium extract, and was linked to a series of serious adverse events — haemorrhagic stroke, heart attack, liver failure and deaths, including two US soldiers who collapsed during training, prompting a military ban and a US regulatory campaign that declared it an unlawful dietary ingredient and seized product. Analytical work established that geranium plants do not contain it in any meaningful amount, making the botanical labelling a fabrication. DMHA, or octodrine, is the successor compound sold on the same model, with the same regulatory position and less data.
Regulation: US regulators declared DMAA an unlawful dietary ingredient, issued warning letters, seized products and won litigation on the point; it has also been banned or restricted in Canada, the UK, Australia, New Zealand, Brazil and elsewhere. DMHA has received the same US warning letters. Both are prohibited in sport by the World Anti-Doping Agency. Products containing them nonetheless remain available, particularly online.
The amounts, forms and durations published trials of DMAA and DMHA actually administered.
These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.
Studied for Amounts found in products
25–75 mg
Per serving of pre-workout or weight-loss product
Typical labelled amounts, where they are labelled at all. There is no safe established dose, no legitimate supplement use, and analyses have found content differing substantially from labels.
This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.
Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.
None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.
Taken before training in the products that contain it. No timing research exists and none is warranted for a banned ingredient.
Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.
What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.
Weight-loss claims rest on stimulant pharmacology alone. No controlled trial supports them, and the adverse event record is what defines this ingredient.
Not enough evidence. Not enough human research to say anything useful yet.
The few small studies conducted before the regulatory action measured haemodynamic responses rather than performance. There is no credible human evidence of a performance benefit, and the substance is banned.
Not enough evidence. Not enough human research to say anything useful yet.
Randomised controlled trial · Human & experimental toxicology · 2013 · PMID 23424215
Clinical trial · BMC pharmacology & toxicology · 2013 · PMID 24090077
Randomised controlled trial · The Physician and sportsmedicine · 2011 · PMID 22030947
Deep research mode adds each paper’s own conclusion and stated limitations.
Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.
Worth knowing
DMAA has been associated with haemorrhagic stroke, myocardial infarction, acute liver failure and deaths, including two soldiers who collapsed during training, which prompted a military-wide withdrawal. US regulators declared it unlawful and pursued seizures and litigation, and many other countries have banned it. DMHA is the successor compound sold on the same model with the same regulatory status.
Worth knowing
Analytical studies established that geranium plants do not contain DMAA in meaningful amounts. The botanical name on the label exists to make a synthetic stimulant look like a plant extract, and the same tactic is used for DMHA with walnut and aconite names.
Worth knowing
Enforcement has not removed these compounds from the market, particularly from online sellers and imported products. A pre-workout listing an unfamiliar botanical alongside a stimulant blend warrants checking the ingredient names against regulatory advisories.
Interaction
Interacts withMAO inhibitors, SSRIs, caffeine, other stimulants, alcohol
Combining an amphetamine-like stimulant with caffeine, MAO inhibitors, SSRIs or other sympathomimetics compounds cardiovascular and neurological risk. Several reported serious events involved such combinations, sometimes with alcohol.
Avoid
Both compounds are on the World Anti-Doping Agency prohibited list and have caused positive tests in athletes who did not know they were in a product.