Common side effects
- Insomnia — the most common complaint. Always take Duromine first thing in the morning, never in the afternoon or evening.
- Dry mouth — keep water handy throughout the day.
- Increased heart rate — your doctor should monitor this.
- Restlessness / jitteriness — similar to too much caffeine.
- Constipation — increase fibre and water intake.
- Elevated blood pressure — monitor regularly.
- Mood changes — irritability or anxiety in some people.
Why Duromine is short-term only
Due to its stimulant nature, Duromine is only prescribed for up to 12 weeks. Longer use carries risks of dependency, tolerance (the effect wears off), and cardiovascular strain. After 12 weeks, your doctor will discuss next steps — which may include switching to a longer-term medication.
Who should NOT take Duromine
- People with cardiovascular disease or uncontrolled high blood pressure
- People with hyperthyroidism or glaucoma
- Anyone with a history of substance misuse
- Pregnant or breastfeeding women
- People taking MAO inhibitors or certain antidepressants
Duromine vs GLP-1 side effects: a key difference
Unlike GLP-1 medications where side effects improve over time (as your body adjusts to each dose), Duromine's stimulant-based side effects tend to persist throughout the entire 12-week treatment. Insomnia, elevated heart rate, and restlessness are inherent to how the medication works — they don't get better because they're the mechanism of action, not a temporary adjustment effect.
This is one reason Duromine is limited to 12 weeks: the cardiovascular strain of sustained elevated heart rate and blood pressure becomes increasingly risky over time.
Managing insomnia specifically
Insomnia is the #1 complaint with Duromine. Practical strategies:
- Take your dose as early as possible — ideally before 8am
- Never take Duromine after midday
- Avoid all caffeine (coffee, tea, energy drinks, chocolate) while on Duromine
- Establish a strict sleep routine: same bedtime, cool room, no screens 1 hour before bed
- If insomnia persists beyond 2 weeks, discuss with your doctor — they may reduce the dose or prescribe a short course of melatonin