Methamphetamine (Desoxyn)

What it treats

Methamphetamine (Desoxyn) is approved by the U.S. Food and Drug Administration for:

• ADHD in children 6 years and older.
• Short-term treatment of exogenous obesity as an adjunct to caloric restriction (rarely used, given the availability of other agents).

Its use for ADHD is limited. Most prescribers reach for other amphetamines or methylphenidate first. Desoxyn sits in the "if other stimulants haven't worked" category for a small group of patients.

How it works

Methamphetamine is an amphetamine derivative with an added methyl group that lets it cross the blood-brain barrier more readily than dextroamphetamine. In the brain, it increases dopamine and norepinephrine, both by causing release and by blocking reuptake. That combination raises signaling in attention and impulse-control circuits, and the effect is felt the same day.

Compared to dextroamphetamine, oral prescribed methamphetamine produces a broadly similar effect at similar doses. The differences in real-world impact between prescribed methamphetamine and the illicit form come mostly from route (oral vs. smoked or injected), dose, and purity.

Receptor mechanism (detail)

Methamphetamine both releases dopamine and norepinephrine and blocks their reuptake at the dopamine and norepinephrine transporters (DAT and NET). It also weakly inhibits monoamine oxidase, though this isn't clinically dominant. The additional methyl group makes it more lipophilic than dextroamphetamine, which is why CNS penetration is faster.

Potency and typical dosing pattern

Ranges are typical framework only, not a prescription for any individual.

ADHD: 5 mg once or twice daily starting, titrated in 5 mg weekly increments to 20 to 25 mg per day divided. Half-life is around 10 to 12 hours.

Safety monitoring

• Baseline and periodic blood pressure, heart rate, weight, and cardiac history, including family history of sudden cardiac death.
• Sleep, appetite, mood at each visit.
• Growth in children. Height and weight at each visit.
• Schedule II controlled substance. Assess for misuse, diversion, and appropriate storage.
• Do not combine with MAOIs (hypertensive crisis).
• Cardiac history. Serious pre-existing structural heart disease warrants careful evaluation before starting.
• Substance use history. Prescribers weigh this carefully given the drug's identity with the street drug.

What to expect

Common side effects

• Reduced appetite, one of the most common effects.
• Trouble sleeping.
• Headache and dry mouth.
• Faster heartbeat.
• Feeling jittery, restless, or anxious.
• Irritability or low mood as a dose wears off.

If any side effect is bothersome or doesn't settle, talk with the prescriber.

Serious side effects and warnings

Boxed warning. Stimulant ADHD medications, including methamphetamine, carry an FDA boxed warning about potential for misuse, abuse, and addiction. Methamphetamine is a Schedule II controlled substance. Used as prescribed and monitored by a clinician, oral prescribed methamphetamine is a stimulant like other amphetamines, but its identity with an illicit drug means prescribers use it selectively and with careful monitoring.

• Cardiovascular effects. Stimulants raise heart rate and blood pressure. Serious pre-existing heart disease warrants careful evaluation.
• Worsening anxiety or agitation.
• Psychotic symptoms. Rare but reported. New hallucinations or unusual paranoid thoughts warrant urgent prescriber contact.
• Slowed growth in children. Height and weight are monitored over time.
• Substance use history. Prescribers factor this in explicitly.
• Circulation problems in fingers and toes (Raynaud's-like), occasional.

Sexual side effects

Prescribed methamphetamine isn't a notable cause of persistent sexual side effects at therapeutic doses. Some people notice changes in libido. If a change occurs, mention it to a prescriber.

Weight, appetite, and sleep

Reduced appetite is common and can lead to weight loss. In children, growth is monitored. Sleep is the other thing to plan around; late-day doses are usually avoided.

Starting and dosing basics

This section is general background, not a dosing instruction for any individual. The right dose is a decision for a prescriber.

Desoxyn comes as 5 mg tablets. Doses are given once or twice daily.

Missed doses and interactions

If a dose is missed, take it when remembered unless it's late in the day. Don't double up. As a Schedule II medication, prescriptions can't be refilled the standard way, and a new prescription is needed each time.

Do not combine with MAOIs. Other stimulants and blood pressure medications need prescriber attention. Give every prescriber and pharmacist the full medication list.

Stopping and tapering

Methamphetamine doesn't require a formal taper. Coordinating stopping with a prescriber matters, because some people notice a period of tiredness, low mood, and reduced motivation after stopping stimulants, and ADHD symptoms are likely to return.

Pregnancy and breastfeeding

Individual circumstances matter, and the decision belongs with a clinician. Anyone pregnant, planning a pregnancy, or breastfeeding should discuss it with their prescriber.

Cost and generic availability

Methamphetamine (Desoxyn) is available as a generic. It is not typically inexpensive because it's rarely stocked, and pharmacies may need to order it. Some plans cover it; others don't.

Common questions

Is this the same drug as the illicit street drug? Chemically, it's the same molecule. Clinically, the differences are enormous: dose, route (oral vs. smoked or injected), purity, monitoring, and setting. Prescribed low-dose oral methamphetamine used under medical supervision has a very different profile from illicit high-dose smoked or injected methamphetamine.

Why is prescribed methamphetamine used at all? Because for a small number of patients, other amphetamines and methylphenidate haven't produced adequate benefit. When it's tried, it's usually after other options have been trialed.

Is it more addictive than Adderall? The prescription setting, dose, and oral route reduce the misuse liability substantially compared with illicit use. Prescribers still assess history and monitor carefully.

Why is this hard to get? Because it's uncommonly prescribed and uncommonly stocked. Ordering can take a few days.

Questions to ask your prescriber

• Why methamphetamine specifically for me over other amphetamines or methylphenidate?
• What are we hoping this treats, and how will we know it's working?
• Which side effects should I expect, and which ones should I call about?
• How will we handle refills, since this needs a new prescription each time?
• If we decide to stop it later, how would we do that?

Sources

This guide draws on current prescribing information and public health references and current as of June 8, 2026. It is reviewed for clinical accuracy and updated as guidance changes.

• U.S. Food and Drug Administration. Methamphetamine (Desoxyn) prescribing information.
• MedlinePlus, U.S. National Library of Medicine. Methamphetamine.
• National Institute of Mental Health. Mental health medications.
• American Academy of Pediatrics. ADHD Clinical Practice Guideline.
• American Psychiatric Association. Practice guidance on ADHD in adults.