Alternatives to Phenelzine If You Can't Fill Your Prescription

Phenelzine (Nardil) is an irreplaceable medication for many patients, but when it's unavailable, your doctor may need to consider alternatives. This guide explains the most clinically relevant options — and what to know before making any switch. Never change your phenelzine dose or stop the medication without first consulting your prescriber.

Why Switching Off Phenelzine Is Complicated

Phenelzine is a non-selective, irreversible MAOI. This means it permanently inactivates the MAO enzyme — the enzyme doesn't recover until your body grows new ones, a process that takes roughly 2 weeks. Any transition away from phenelzine must account for:

A mandatory 14-day washout period before starting most other antidepressants

Risk of withdrawal syndrome if stopped abruptly (vivid nightmares, agitation, psychosis, seizures beginning 24–72 hours after stopping)

Individual patient response — what worked as a phenelzine alternative for one patient may not work for another

Alternative 1: Tranylcypromine (Parnate)

Tranylcypromine is the most studied MAOI antidepressant and is often the first alternative considered when phenelzine is unavailable. Like phenelzine, it is a non-selective, irreversible MAOI and requires the same tyramine-restricted diet. Key differences:

Comes in 10 mg tablets; typical dose 30–60 mg/day

Less likely to cause weight gain and sexual dysfunction than phenelzine

May be slightly more stimulating/activating; less sedating than phenelzine

Not associated with pyridoxine (B6) deficiency or hepatotoxicity, unlike phenelzine

Note: You cannot switch directly from phenelzine to tranylcypromine. A 14-day washout is required between any two MAOIs.

Alternative 2: Isocarboxazid (Marplan)

Isocarboxazid is another hydrazine MAOI, chemically more similar to phenelzine than tranylcypromine is. It is generally considered the third choice among the classic oral MAOIs, but some patients tolerate it better than phenelzine. Key characteristics:

Comes in 10 mg tablets; approved up to 60 mg/day

Some meta-analyses suggest it outperforms placebo more robustly than phenelzine or tranylcypromine

Requires same dietary restrictions as other oral MAOIs

Less commonly prescribed, so availability at pharmacies may also be limited

Alternative 3: Selegiline Patch (Emsam)

The selegiline transdermal patch (Emsam) is the only MAOI available as a skin patch and the only one FDA-approved for major depressive disorder at all doses. It offers a significant practical advantage: at the lowest dose (6 mg/24 hours), no dietary tyramine restrictions are required. Key points:

Available in 6 mg, 9 mg, and 12 mg/24-hour strengths

At 6 mg/24hr, dietary restrictions are not required — a major quality-of-life improvement

Generally considered less effective than oral MAOIs for treatment-resistant cases

Can cause skin irritation at the application site

What About SSRIs, SNRIs, or Other Antidepressants?

Many patients on phenelzine are prescribed it specifically because SSRIs (like fluoxetine or sertraline), SNRIs, and other first-line antidepressants have already failed. In those cases, switching to another SSRI or SNRI is unlikely to be effective.

However, if your doctor determines a non-MAOI option is appropriate, at least 14 days must pass after stopping phenelzine before starting any serotonergic agent (SSRIs, SNRIs, certain TCAs). Serotonin syndrome, a potentially life-threatening condition, can occur if this washout is not observed.

The Bottom Line: Talk to Your Prescriber First

No alternative to phenelzine should be started without medical supervision. If phenelzine is temporarily unavailable, read our guide on why phenelzine is hard to find and how to locate it — often the best solution is finding a pharmacy that stocks it rather than switching medications.

If your current pharmacy is out of stock, medfinder can call pharmacies near you to find one with phenelzine in stock — saving you hours of phone calls.