Has Anyone Successfully Fasted While on Antidepressants? Any Interactions I Should Know About?

Has Anyone Successfully Fasted While on Antidepressants? Any Interactions I Should Know About?

The Short Answer

Yes — many people fast successfully while taking antidepressants. But the interaction between fasting and specific medications matters. Some antidepressants must be taken with food to reduce gastrointestinal side effects or maintain stable absorption. Others have specific considerations around blood sugar or timing. The right first step is to review your specific medication's requirements with your prescribing doctor or pharmacist — and let them know you're planning to fast intermittently.

The Full Explanation

Antidepressants are not a single category. SSRIs, SNRIs, tricyclics, MAOIs, and atypical antidepressants all have different profiles, different dosing requirements, and different interactions with an empty stomach. Here's what to understand for the most common classes.

SSRIs (e.g., sertraline, fluoxetine, escitalopram, paroxetine)

The most widely prescribed class. Most SSRIs can technically be taken with or without food, but many patients take them with food because nausea is a common side effect on an empty stomach — particularly in the first few weeks of use. If your eating window is in the morning or midday, you can time your medication with your first meal and avoid most of the GI discomfort. If you're on an evening eating window, taking an SSRI during the fasting hours might be uncomfortable.

One thing worth knowing: some SSRIs influence appetite and blood sugar regulation. Fluoxetine (Prozac) suppresses appetite in some people — fasting combined with this effect can occasionally lead to under-eating. Paroxetine is associated with weight gain in some users, and fasting may counteract this, but that interaction deserves monitoring rather than self-managing in isolation.

SNRIs (e.g., venlafaxine, duloxetine)

Similar to SSRIs in terms of GI side effects on an empty stomach. Venlafaxine in particular is better tolerated with food. Extended-release formulations tend to be more stable in absorption and are generally easier to work around with a fasting schedule.

Bupropion (Wellbutrin, Zyban)

This one warrants specific attention. Bupropion lowers the seizure threshold, and this risk is dose-dependent. It should generally be taken with food, particularly at higher doses. Fasting while on bupropion is possible but deserves an explicit conversation with your prescribing doctor about when and how to take it relative to your eating window.

Tricyclic antidepressants (e.g., amitriptyline, nortriptyline)

These older medications are often used at lower doses for pain management or sleep now. They're sedating and commonly taken at night. If you're taking them before bed, you can structure your eating window to include food before your evening dose without any conflict with a morning or midday fast.

MAOIs (e.g., phenelzine, tranylcypromine)

MAOIs have significant dietary restrictions — they require strict avoidance of tyramine-rich foods. Fasting is possible, but the dietary discipline already required for MAOI use is high. Anyone on MAOIs considering intermittent fasting should discuss this specifically with their prescribing physician before changing anything.

The Blood Sugar Question

Some antidepressants — particularly certain SSRIs — can affect blood sugar regulation. In people with diabetes or pre-diabetes, this can interact with the blood sugar drops that occur during a fasting window. If you're managing blood sugar alongside antidepressant use, monitoring glucose levels during your fasting window (especially in the first few weeks) is sensible. Understanding what happens to your body during intermittent fasting can help you interpret what you're seeing.

Mood Stability During Fasting

Blood sugar stability is linked to mood for many people. Some individuals find they become more irritable, anxious, or emotionally flat during extended fasting windows — particularly in the first few weeks. For someone already managing depression, this temporary effect can be unsettling. It generally eases as the body adapts to using fat as fuel, but if mood symptoms worsen significantly during fasting, shorten the window and speak to your doctor before continuing.

Practical Tips

  1. Tell your doctor before you start. Your prescribing doctor may need to adjust the timing of your dose, confirm whether your specific medication requires food, or flag any known interactions with blood sugar changes.
  2. Time medication with your eating window. In most cases, you can structure your eating window to overlap with your dose. If your window is 12pm–8pm, take medication with lunch or dinner.
  3. Watch for increased GI side effects. If you develop nausea or stomach discomfort from taking medication during the fasting window, adjust the timing rather than pushing through.
  4. Break the fast with protein and fat. A protein-rich first meal helps stabilise blood sugar quickly and provides the amino acid building blocks that support serotonin and dopamine synthesis — relevant for anyone on antidepressants.
  5. Start with a shorter window. If you're adjusting medication or recently changed your dose, begin with 12–13 hours of fasting rather than jumping to 16:8. Build slowly once you feel stable.

For more on managing mood-related effects during fasting, see does intermittent fasting improve mood?.

For the complete guide to intermittent fasting, get Intermittent Fasting in Practice on Amazon. Buy the book and claim 3 months free on our fasting app at https://www.fastinginpractice.com/redeem.

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This content is for informational purposes only and does not constitute medical advice. Always consult a healthcare professional before making changes to your diet or medication routine.