Prescription methamphetamine is FDA-approved to treat attention deficit hyperactivity disorder (ADHD) in children aged 6 and older. It also carries an older approval for short-term treatment of obesity that has not responded to other interventions. Sold under the brand name Desoxyn, it is the only legal form of methamphetamine available in the United States and is far less commonly prescribed than other stimulants like Adderall or Ritalin.
ADHD in Children
The primary use for prescription methamphetamine is ADHD. The FDA approves Desoxyn specifically for pediatric patients 6 years of age and older. Treatment typically starts at 5 mg taken once or twice daily, and the dose can be increased by 5 mg each week based on how the child responds. Most patients end up in the 20 to 25 mg per day range.
In practice, Desoxyn is rarely the first stimulant a doctor reaches for. Medications like mixed amphetamine salts (Adderall) and methylphenidate (Ritalin, Concerta) are far more widely prescribed and come in a broader range of formulations, including extended-release versions. Desoxyn is generally reserved for cases where those more common options haven’t worked well enough or caused intolerable side effects. It functions as a last-line stimulant rather than a starting point.
Short-Term Weight Loss
Desoxyn also carries FDA approval for what the label calls “exogenous obesity,” meaning weight gain caused by overeating rather than a hormonal or metabolic condition. This use is tightly restricted. It is only approved as a short-term add-on, limited to a few weeks, for patients whose obesity has not responded to repeated diets, group programs, or other weight-loss medications. The dose for this purpose is lower: a single 5 mg tablet taken half an hour before each meal.
This indication is largely a relic of an earlier era in medicine, when amphetamine-class drugs were more commonly prescribed as appetite suppressants. Today, newer medications with fewer risks have replaced stimulants for weight management, and it is extremely uncommon for a doctor to prescribe methamphetamine for this purpose.
How It Works in the Brain
Methamphetamine increases the levels of several chemical messengers in the brain, most notably dopamine and norepinephrine. It does this in a few ways at once: it reverses the transporters that normally pull these chemicals back into nerve cells, disrupts the storage packets that hold them inside cells, and slows the enzymes that break them down. The net effect is a surge of dopamine and norepinephrine in the spaces between neurons.
For someone with ADHD, that boost in dopamine and norepinephrine improves focus, reduces impulsivity, and helps regulate attention. The mechanism is essentially the same as other prescription stimulants. Methamphetamine is roughly 10 times more potent on a milligram-for-milligram basis than methylphenidate (Ritalin), which is one reason doses are kept low and the drug is prescribed cautiously.
How It Compares to Other Stimulants
On paper, methamphetamine sits in the same drug class as amphetamine (Adderall) and methylphenidate (Ritalin). All three are Schedule II controlled substances under federal law, meaning the DEA considers them to have a high potential for abuse and dependence. Methamphetamine and amphetamine are roughly equal in potency, while methylphenidate is considerably weaker per milligram.
The critical difference is practical, not pharmacological. Adderall and Ritalin come in dozens of formulations, including long-acting capsules that release medication steadily over 8 to 12 hours. Desoxyn is only available as an immediate-release tablet, which means it wears off faster and typically needs to be taken more than once a day. Combined with the stigma attached to the word “methamphetamine” and the drug’s association with illegal use, this makes it a niche prescription that most pharmacies do not routinely stock.
Regulatory Controls
Because methamphetamine is a Schedule II substance, prescriptions come with strict rules. Refills are not allowed. Each time you need more, your doctor must write a new prescription. The prescription cannot be called in by phone in most circumstances and must follow federal and state dispensing regulations.
Desoxyn is currently manufactured by Recordati Rare Diseases, a specialty pharmaceutical company. Its limited production and narrow patient base mean many pharmacies need to special-order it, which can add days to filling a prescription.
Risks and Side Effects
The side effects of prescription methamphetamine are similar to those of other stimulants: decreased appetite, trouble sleeping, increased heart rate, and elevated blood pressure. Because the drug is a potent stimulant, cardiovascular effects are a particular concern. People with a history of heart problems, uncontrolled high blood pressure, or structural heart defects are generally not candidates for this medication.
The risk of dependence is real but context-dependent. At the low, controlled doses used for ADHD (5 to 25 mg per day, taken by mouth), the drug behaves differently in the body than when it is smoked or injected at high doses. Oral use produces a slower, more gradual rise in brain dopamine, which is far less likely to produce the intense rush associated with addiction. Still, the potential for misuse is the main reason Desoxyn remains a last-resort option, prescribed only when safer alternatives have failed.
Why It Still Exists
It is reasonable to wonder why a drug with this much stigma remains on the market at all. The answer is that for a small number of patients, it works when nothing else does. Some children and adults with ADHD respond better to methamphetamine than to amphetamine or methylphenidate, likely because of individual differences in how their brains metabolize these drugs. Keeping it available as a legal, pharmaceutical-grade option gives doctors one more tool for treatment-resistant cases, even if they rarely need to use it.