DMAA and DMHA are synthetic stimulants found in pre-workout and weight loss supplements. Both mimic the effects of adrenaline in the body, raising blood pressure, increasing heart rate, and producing a burst of energy and focus. Despite being marketed as natural plant extracts, both compounds have drawn serious safety concerns and regulatory action from the FDA.
DMAA: The Original “Geranium Extract”
DMAA (1,3-dimethylamylamine), also called methylhexaneamine, is an alkylamine structurally related to amphetamine. It was first studied in the 1940s and 1950s, when researchers documented its ability to mimic adrenaline throughout the body. It constricts blood vessels, raises blood pressure, speeds up heart rate, and increases blood sugar. These properties made it appealing to supplement companies looking for powerful stimulant ingredients, and DMAA became a staple in pre-workout formulas through the 2000s and early 2010s.
Supplement labels frequently listed DMAA as “geranium extract” or “geranium oil,” implying it was a naturally derived ingredient. That claim has been thoroughly tested. When researchers examined eight different commercial geranium extracts from China and the Middle East using sensitive mass spectrometry, no DMAA was detected in any of them, even at concentrations as low as 10 parts per billion. The chemical ratios of DMAA found in supplements were also indistinguishable from synthetic laboratory standards. In short, the DMAA in your pre-workout was made in a lab, not extracted from a plant.
DMHA: The Replacement Stimulant
DMHA (dimethylhexylamine), sold under the trade name Octodrine, is a closely related stimulant that gained popularity as DMAA faced increasing regulatory pressure. It works by increasing the activity of dopamine and noradrenaline, two brain chemicals involved in alertness, motivation, and the sensation of energy. Users typically describe the effects as similar to DMAA but somewhat milder.
Like DMAA, DMHA exists in two forms. One occurs naturally in trace amounts in walnut bark (Juglans regia) and a few other plants, which is why some supplement labels list “walnut bark extract” or “Juglans regia extract” as ingredients. The second form is synthetically produced, and that version is what actually appears in most supplements. The distinction matters because it allows manufacturers to frame a synthetic stimulant as a botanical ingredient.
What They Feel Like and How They Differ
Both DMAA and DMHA produce a noticeable surge in energy, focus, and sometimes euphoria, which is why they became popular in fitness supplements. The practical difference comes down to potency and dosage. Supplements containing DMAA have been found to contain anywhere from 50 mg to 278 mg per serving. DMHA supplements typically contain lower amounts, with doses up to 72 mg per serving detected in tested products.
In controlled testing, a 25 mg dose of DMAA produced measurable increases in blood pressure. At 50 mg and 75 mg, those increases climbed to roughly 8 and 12 mmHg, respectively. That may not sound dramatic, but for someone already on the borderline of high blood pressure, or stacking DMAA with caffeine (as most pre-workout formulas do), the cardiovascular strain adds up quickly. No equivalent controlled dosing studies exist for DMHA, which is part of what makes it concerning: people are taking it with very little clinical data on what it does at supplement-level doses.
Cardiovascular and Neurological Risks
The FDA has linked DMAA to a range of serious cardiovascular events. By narrowing blood vessels and arteries, DMAA can cause shortness of breath, chest tightness, irregular heart rhythms, and heart attack. Neurological effects include seizures and psychological disturbances. These risks increase significantly when DMAA is combined with caffeine, which is nearly universal in the supplements that contain it.
The most alarming reports involve bleeding in the brain. A published case series documented three adults who suffered cerebral hemorrhages after using DMAA, including subarachnoid hemorrhage, a particularly dangerous type of brain bleed. One reported case involved a person who took two capsules containing 278 mg of DMAA each (a total of 556 mg) along with caffeine and alcohol. That total dose was roughly 10 times what researchers used in controlled studies.
DMHA carries similar theoretical risks given its shared mechanism of action, but fewer case reports exist simply because it entered the market more recently. The absence of documented emergencies is not the same as evidence of safety.
FDA and Regulatory Status
The FDA considers DMAA an illegal ingredient in dietary supplements. Products containing it are classified as adulterated, meaning they violate federal food safety law. The agency has issued multiple rounds of warning letters to manufacturers, and several high-profile DMAA-containing products have been pulled from the market.
DMHA followed a similar path. In April 2019, the FDA issued nine warning letters to companies selling supplements containing DMHA, determining that it is either a “new dietary ingredient” lacking required safety notifications or an unsafe food additive. Supplements containing DMHA are also considered adulterated under federal law.
Despite these actions, both substances still appear in supplements sold online and in some retail stores. Manufacturers sometimes use obscure synonyms or botanical names on labels to avoid detection. If you see terms like methylhexaneamine, 1,3-dimethylpentylamine, octodrine, 2-amino-6-methylheptane, or Juglans regia extract on a supplement label, you’re looking at DMAA or DMHA.
Status in Competitive Sports
The World Anti-Doping Agency (WADA) prohibits both substances during competition. DMAA is listed under methylhexaneamine as a specified stimulant in Section 6.b of the prohibited list. DMHA is listed under its trade name, octodrine, in the same category. “In-competition” means the ban applies on race or game day and the period immediately surrounding it, not during off-season training. However, because DMAA can remain detectable in the blood for many hours after ingestion (one case showed measurable levels 17 hours after a dose), athletes face a real risk of testing positive even if they took the substance well before competition.
Multiple athletes across various sports have received suspensions after testing positive for DMAA or DMHA, sometimes claiming they didn’t know the ingredient was in their supplement. This is one of the clearest practical risks for anyone competing in drug-tested sport: the ingredient may appear on a label under a name you don’t recognize, but the test result and the ban will be the same regardless.