Phenelzine (Nardil): How This MAOI Works, Diet Rules, Dosing, and When Telehealth Is Enough

Last updated: August 22, 2026

Phenelzine is a monoamine oxidase inhibitor (MAOI). The brand name is Nardil. Clinicians usually reserve it for depression that has not responded to other medicines, including atypical or “neurotic” depression on the U.S. label. It is not a first-line antidepressant. It is not a controlled substance. The hard parts are the tyramine diet, a long list of drug interactions, and the risk of hypertensive crisis or serotonin syndrome. A licensed telehealth clinician can often follow a stable adult who already knows the diet. New starts need a full medication and food review, and any sudden severe headache or suspected overdose is an emergency.

This guide is educational. It is not a diagnosis and it is not a promise that any clinician will prescribe phenelzine.

Looking for depression care online? Klarity Health has 2,000+ licensed providers. Many visits happen by video. Coverage varies by plan. Self-pay is also an option. See online depression treatment options or browse conditions.

TLDR

• Phenelzine is a nonselective, irreversible MAOI. MedlinePlus a682089 lists it for depression in people who have not been helped by other medications. Brand: Nardil.
• NAMI (reviewed December 2024) lists FDA approval for atypical, nonendogenous, or neurotic depression. Tablets: 15 mg. Usual daily range 15 to 90 mg, often three to four times a day.
• The Nardil label on DailyMed (setid 513a41d0) starts at one 15 mg tablet three times a day, then rises fairly quickly toward at least 60 mg per day as tolerated. Some people need up to 90 mg per day. Many people do not respond until they have been on 60 mg for at least 4 weeks. After benefit, the dose is reduced slowly. Maintenance can be as low as 15 mg daily or every other day. See DailyMed Nardil.
• StatPearls phenelzine (NBK554508) (updated March 6, 2023) describes it as a later-line option after SSRIs and other first-line drugs. Mean half-life after a single 30 mg dose is about 11 to 12 hours. Clinical benefit often starts around 2 weeks; 6 to 8 weeks may be needed to judge the full effect.
• Boxed warning: antidepressants raised suicidal thinking and behavior versus placebo in children, adolescents, and young adults in short-term studies. MedlinePlus says children younger than 18 should not normally take phenelzine. DailyMed: safety and effectiveness in the pediatric population have not been established.
• You must avoid high-tyramine foods (aged cheeses, dry sausages, pickled herring, liver, fava bean pods, yeast extract, beer and wine, yogurt on the label list) and excess caffeine or chocolate. The diet continues for about 2 weeks after the last dose. Hypertensive crisis is a medical emergency.
• Do not combine with other MAOIs, SSRIs, SNRIs, most other antidepressants, meperidine, many opioids, triptans, linezolid, IV methylene blue, buspirone, stimulants, or St. John’s wort. NAMI: wait 2 weeks when you switch (5 weeks after fluoxetine). StatPearls: allow 3 to 4 weeks from stopping phenelzine before another antidepressant in many cases.
• Not a controlled substance. Telehealth can follow many stable adults who already keep the diet. Chest pain, sudden occipital headache, stiff neck, high fever, confusion, or any suspected overdose need emergency care. If you are in crisis, call or text 988.

Table of contents

• What phenelzine is
• How it works
• Approved and related uses
• Phenelzine dosage
• Tyramine diet and hypertensive crisis
• Side effects
• Warnings and who should not take it
• Interactions
• When telehealth is enough
• How a Klarity visit fits
• FAQ

What phenelzine is

Phenelzine is an oral tablet. DailyMed and NAMI list 15 mg film-coated tablets (phenelzine sulfate equivalent to 15 mg phenelzine base). Product names are not interchangeable without a clinician and pharmacist check. DEA schedule: none.

Brand: Nardil. Related Klarity antidepressant guides: amitriptyline (Elavil), nortriptyline (Pamelor), trazodone, mirtazapine (Remeron), venlafaxine (Effexor), and bupropion (Wellbutrin).

How it works

MedlinePlus says phenelzine increases certain natural substances needed to maintain mental balance. StatPearls describes it as a potent, nonselective, irreversible inhibitor of monoamine oxidase A and B. That slows the breakdown of serotonin, norepinephrine, and dopamine. It also raises GABA in the brain. The enzyme block lasts after a single tablet is gone, which is why diet and drug rules continue for weeks after you stop.

DailyMed: after a single 30 mg dose (two 15 mg tablets), mean peak plasma concentration was 19.8 ng/mL at 43 minutes. StatPearls: mean elimination half-life after 30 mg is about 11 to 12 hours. The manufacturer has not fully studied multiple-dose pharmacokinetics in humans.

NAMI: sleep, energy, or appetite may shift in 1 to 2 weeks. Depressed mood and interest may take 6 to 8 weeks. StatPearls: benefit often starts around 2 weeks; if there is no intended result by 6 to 8 weeks, a higher dose may be needed. MedlinePlus: full benefit may take 4 weeks or longer.

Approved and related uses

MedlinePlus lists phenelzine for depression when other medicines have not helped. NAMI and the DailyMed indication language focus on atypical, nonendogenous, or neurotic depression. StatPearls notes evidence is less conclusive in severely depressed people with endogenous (major depressive) features, and that clinicians often use it after first-line options fail.

StatPearls also notes investigation in panic disorder, social anxiety, pediatric selective mutism (unlabeled; data mixed), historic off-label use in bulimia, and consideration in OCD. Those uses are not FDA-approved on the sources retrieved for this article. Phenelzine is not FDA-approved for bipolar disorder. A licensed clinician decides after a full history.

Phenelzine dosage

Only your prescriber sets the dose. Typical labeled and StatPearls ranges:

• Start (DailyMed / NAMI): 15 mg three times a day.
• Titration (DailyMed): increase fairly quickly toward at least 60 mg per day as tolerated. Some people need up to 90 mg per day to get enough MAO inhibition. Many people do not show a clinical response until they have taken 60 mg for at least 4 weeks.
• Maintenance (DailyMed): after maximum benefit, reduce slowly over several weeks. Maintenance may be as low as 15 mg daily or every other day, for as long as needed.
• Elderly (StatPearls): often 15 to 60 mg daily in divided doses; start as low as 7.5 mg daily and rise by 7.5 to 15 mg every 3 to 4 days as tolerated.
• Missed dose (MedlinePlus / NAMI): take it when you remember unless it is almost time for the next dose. Do not double.

Do not stop suddenly. MedlinePlus lists withdrawal symptoms such as nightmares, agitation, loss of contact with reality, nausea, vomiting, and weakness. NAMI adds irritability, dizziness, headache, and paresthesias. Your clinician tapers.

Tyramine diet and hypertensive crisis

MAO in the gut normally breaks down tyramine in food. When you block it, tyramine can push blood pressure into a dangerous range. DailyMed, MedlinePlus, NAMI, and StatPearls all require a low-tyramine diet during treatment and for about 2 weeks after the last dose (NAMI).

Foods and drinks commonly listed to avoid:

• Aged cheeses (parmesan, aged cheddar, blue cheese, and similar)
• Dry sausages: salami, pepperoni, Genoa salami, Lebanon bologna
• Pickled herring, liver, yeast extract (including large amounts of brewer’s yeast)
• Beer and wine, including some reduced-alcohol products
• Fava or broad bean pods, sauerkraut, yogurt (on the DailyMed list)
• Smoked, pickled, fermented, aged, spoiled, or poorly stored high-protein foods
• Excess caffeine and chocolate

Your clinician or a dietitian should give you a full list. Freshness matters. If food may be spoiled or poorly refrigerated, skip it.

NAMI lists hypertensive-crisis symptoms: occipital headache that starts in the back of the head and moves forward, palpitations, nausea or vomiting, neck stiffness or soreness, light sensitivity, sweating. That is emergency care, not a message-the-portal problem.

Side effects

Common effects on NAMI: sedation, dry mouth, weight gain, low blood pressure, headache, constipation, sexual dysfunction, blurred vision, urinary retention. StatPearls adds orthostatic dizziness, constipation, dry mouth, weight change, anorgasmia or impotence, and nausea. MedlinePlus: drowsiness and dizziness when you stand quickly, especially at the start. Get up slowly.

Serious events that need urgent care: hypertensive crisis, intracranial bleeding tied to severe hypertension, serotonin syndrome (shivering, diarrhea, confusion, severe muscle tightness, fever, seizures), seizures, liver injury, worsening mood or suicidality, and overdose. StatPearls also notes research linking phenelzine to vitamin B6 deficiency; some people need supplementation. Overdose: call 911 or poison control at 1-800-222-1222 (NAMI). There is no specific reversal agent.

Warnings and who should not take it

Boxed suicidality warning applies, as with other antidepressants. Watch for new or worse depression, suicidal thinking, agitation, panic, insomnia, aggression, or mania, especially after starts or dose changes. DailyMed: write the smallest quantity consistent with good care to reduce overdose risk.

Do not take phenelzine if you have pheochromocytoma, congestive heart failure, severe kidney disease, abnormal liver tests, or a history of liver disease (StatPearls / MedlinePlus). Tell your clinician about high blood pressure, diabetes (glucose may need closer checks), seizures, schizophrenia, agitation, movement disorders, planned surgery or dental work, pregnancy, or breastfeeding. StatPearls: pregnancy Category C; human data are limited; hypertensive crisis in pregnancy can harm the fetus. NAMI: MAOIs are generally not recommended in pregnancy. Alcohol can worsen side effects; do not drink while you take it (MedlinePlus).

If you are in crisis, call or text 988. If someone may have overdosed, call 911.

Interactions

The interaction list is long. Bring every prescription, OTC product, supplement, and any stimulant or opioid use to the visit. Highlights from DailyMed, NAMI, and StatPearls:

• Other MAOIs, SSRIs, SNRIs, TCAs, bupropion, mirtazapine, buspirone: serotonin syndrome or other serious reactions. Washout is usually at least 14 days; NAMI uses 5 weeks after fluoxetine.
• Meperidine is contraindicated. Many other opioids (tramadol, fentanyl, methadone, and others on NAMI’s list) raise risk. StatPearls strongly discourages combining phenelzine with opioids.
• Sympathomimetics: amphetamines, cocaine, methylphenidate, dopamine, epinephrine, norepinephrine, many cold tablets and nasal decongestants.
• L-dopa, L-tryptophan, L-tyrosine, phenylalanine, aspartame-sweetened products in some cases (MedlinePlus).
• Triptans, linezolid, methylene blue, St. John’s wort, cyclobenzaprine, carbamazepine, dextromethorphan.
• Guanethidine: wait at least 2 weeks after stopping the MAOI (DailyMed).

Phenelzine can stay in your system for weeks after the last tablet. Tell every new clinician and pharmacist you recently stopped it (MedlinePlus).

When telehealth is enough

Phenelzine is not a controlled substance, so DEA schedule is not the barrier. The barrier is safety: diet teaching, a complete medication list, blood-pressure checks, and a plan for hypertensive crisis. Video care can work well for adults already stable on a known dose who can keep the diet and who have a local plan for labs or urgent blood pressure care. New starts, people who cannot reliably avoid tyramine, people on many interacting drugs, and anyone with liver or severe kidney disease usually need more than a single video visit.

Hypertensive crisis, suspected serotonin syndrome, chest pain, fainting, seizures, or overdose belong in an emergency department. Telehealth does not replace that.

How a Klarity visit fits

Klarity Health connects adults with 2,000+ licensed providers for video visits. A clinician can review depression history, prior medicine trials, blood pressure, diet ability, and whether an MAOI is even appropriate. Many people do better first on an SSRI, SNRI, or other option. If phenelzine is already working and you need follow-up, a video visit may be enough. Coverage varies by plan. Verify benefits before you book. Self-pay is also an option.

See online depression treatment options · Browse conditions

Disclaimer: Insurance coverage varies by plan. This article does not promise that any plan will pay for phenelzine, labs, or a visit. Confirm benefits with your insurer. This is education, not medical advice. If you are in crisis, call or text 988.

FAQ

Is phenelzine the same as Nardil?

Nardil is the brand. Phenelzine is the generic. Both refer to 15 mg tablets of phenelzine sulfate on NAMI and DailyMed.

How long does phenelzine take to work?

NAMI: physical symptoms may ease in 1 to 2 weeks; mood may take 6 to 8 weeks. DailyMed: many people do not respond until they have been on 60 mg for at least 4 weeks. MedlinePlus: 4 weeks or longer is common.

Can I get phenelzine through telehealth?

Sometimes, for a stable adult who already follows the diet and has no interacting drugs. A clinician still has to decide. New starts need a careful review. No article can promise a prescription.

What foods must I avoid on phenelzine?

Aged cheeses, dry sausages, pickled herring, liver, fava bean pods, yeast extract, beer and wine, yogurt on the label list, and spoiled or poorly stored high-protein foods. Limit caffeine and chocolate. Ask your clinician for the full list and keep it for 2 weeks after you stop.

Is phenelzine a controlled substance?

No. DailyMed does not schedule it. The safety rules still apply.