Caveat to this post. Only a few groups of people really need to think about tyramine: those on MAOI antidepressants and those on certain antibiotics including linezolid and furazolidone. Linezolid requires minimal caution if you have otherwise normal blood pressure, though please see below for sex differences.

Background

Tyramine results from bacteria eating protein. Specifically, tyrosine, an amino acid common to protein-rich foods, gets its carboxyl group snipped off by microbes, and the leftover is tyramine. Thus, the more bacterial protein breakdown a food has gone through, the higher its tyramine content will be. Fresh foods are safe while aged, fermented, cured, and spoiled foods all have higher levels.

When you ingest tyramine an enzyme called monoamine oxidase (MAO) destroys it in your gut before it reaches your blood stream. When MAOI antidepressants and antibiotics block that enzyme, tyramine gets into the blood stream inducing norepinephrine release. This causes blood pressure to spike high enough that it can cause a "hypertensive crisis".¹

Antibiotics that can cause tyramine issues:

• linezolid (Zyvox)² — yes. A reversible, non-selective MAO inhibitor; a significant blood-pressure response appears at tyramine doses over 100 mg, so the label warns against tyramine-rich foods.
• furazolidone (Furoxone)³ — yes, but cumulative. The MAO-inhibiting effect builds over days: roughly 5 days of dosing raises tyramine sensitivity about 2–3 fold.
• tedizolid (Sivextro)⁴ — unlikely. A reversible MAO inhibitor in vitro but weak in practice: the tyramine dose needed to push systolic blood pressure up 30 mmHg fell only from 425 mg (placebo) to 325 mg, so it generally needs no dietary caution.

Danger zones:

• 600 mg for a healthy person not on any MAOI⁵ — the EFSA no-observed-adverse-effect level (NOAEL); measurable pressor responses (a 30 mmHg systolic rise) can appear at lower doses in sensitive individuals (see the 200–800 mg PD30 range below), but are not classified as clinically adverse below this threshold
• ~325 mg the median tyramine dose that provokes a pressor response on tedizolid (Sivextro) — several times more than any normal meal delivers, which is why it needs no dietary caution⁴
• ~100 mg Linezolid's FDA labelling ²
• 50 mg for someone on a newer (third-generation) MAOI⁵
• 6 mg for someone on a classic irreversible MAOI like phenelzine or tranylcypromine⁵

For the classic MAOIs a dose–response framing is similar⁶: ~6 mg starts mild symptoms, 10–25 mg risks a severe reaction, and the average un-medicated person tolerates 200–800 mg before their blood pressure changes.

Also note: tyramine levels in food have decreased over time. Non-decarboxylating starter cultures and refrigeration mean today's supermarket cheddar, salami, and soy sauce carry a fraction of the tyramine of the mid-century samples that produced terrifying guidance in the past⁷.

Tapering

How quickly you can relax tyramine restrictions after stopping a drug depends on whether the MAO inhibition is reversible and how fast the drug clears.

Do you really need to worry about tyramine on linezolid

The FDA label warns against large amounts of tyramine-rich foods, based on controlled studies in which pressor responses appeared at oral tyramine doses above 100 mg. Three independent clinical studies suggest the practical risk from ordinary eating is substantially lower — though all three were conducted in healthy male volunteers with normal blood pressure. There is no tyramine–linezolid literature on patients with pre-existing hypertension, and none on women; see the sex differences section below.

A note on methods: the studies below define a pressor response as a ≥30 mmHg systolic rise — a threshold Cantarini et al.¹¹ describe as "clinically inconsequential (increases in SBP of 30 mmHg occur during mild to moderate exercise)" — and they establish thresholds using overnight fasting and, in one case, intravenous tyramine, both of which substantially overstate real dietary exposure.

Antal et al. (J Clin Pharmacol 2001;41:552–562)¹⁰ gave healthy male volunteers oral tyramine challenges alongside linezolid or moclobemide, after an overnight fast (midnight until 2 hours after the final tyramine dose; meals not until 15:00). The smallest dose raising systolic BP ≥30 mmHg was 100 mg on linezolid versus 75 mg on moclobemide, with pressor sensitivity ratios of 3.48 versus 4.97. Their abstract concludes: "The MAOI activity of linezolid is similar to that of moclobemide, a drug used clinically without food restrictions. Restrictions to normal dietary intake of tyramine-containing foods are not warranted when taking linezolid."

Cantarini et al. (Br J Clin Pharmacol 2004;58(5):470–475)¹¹, using intravenous tyramine in a within-subject crossover (n = 12), found TSF 1.8 (90% CI 1.6–2.0) for linezolid versus 2.1 (90% CI 1.8–2.4) for moclobemide — statistically indistinguishable, corroborating the equivalence. They also found a statistically significant effect of BMI on TYR30 (p = 0.002): each 1-unit increase in BMI produced a ~4.6% increase in the tyramine dose needed — projecting this linearly, a 10-unit BMI increase would correspond to roughly 57% more tyramine tolerated, though the true relationship could be nonlinear, could saturate, or could steepen at the extremes.

Rumore, Roth & Orfanos (Nutr Clin Pract 2010;25:265–269)¹² found zero published case reports of a linezolid–tyramine reaction in hospital patients (only one outpatient case reported to the manufacturer, details unknown). They also noted that the Antal 100 mg threshold was established in fasted subjects; consuming tyramine with a meal reduces bioavailability by ~50%¹³, and in a study of moclobemide subjects, 2.8× higher oral doses were needed in fed versus fasted subjects to produce a pressor response¹⁴ — suggesting the effective dietary threshold is substantially higher than the fasting experimental figure. New York–Presbyterian Hospital (>2,300 beds) removed the tyramine-restriction requirement for linezolid patients in December 2009 and reported no problems. Their conclusion: "dietary restrictions of tyramine are not necessary for hospitalized patients on linezolid."

The bottom line: linezolid and moclobemide have essentially identical tyramine sensitivity, and moclobemide is prescribed without dietary tyramine restriction. The "Safe on AB" column below (100 mg ceiling, ~3× margin) is a sound and conservative guide for men with normal blood pressure; women may need to apply a more cautious margin (see the sex differences section below). Genuine caution on linezolid is warranted only for extreme foods: aged or spoiled chicken liver (~2,000 mg/kg), worst-case legacy Genoa salami (up to 1,237 mg/kg), acid-curd cheese outliers (up to 2,000 mg/kg), 1974-vintage US "Swiss" (up to 1,800 mg/kg), Dutch pickled herring (up to 3,000 mg/kg), fermented fish pastes, and the heaviest fermented shrimp and soybean pastes. Normal restaurant and supermarket portions of ordinary cheese, cured meat, beer, and wine are not a realistic threat.

If you have pre-existing hypertension or are female, you fall outside the studied population and prudence warrants closer attention to the limits.

Sex differences in tyramine sensitivity

All three linezolid clinical studies above enrolled only men. Two earlier studies quantify the baseline sex difference in tyramine sensitivity in unmedicated subjects.

Reimann et al. (Eur J Clin Pharmacol 1992;42:137–141)¹⁵ gave IV tyramine to 55 healthy unmedicated volunteers (34 male, 21 female) after a 12-hour fast. Mean PD30 was 4.6 mg (SD 1.1) for males versus 3.5 mg (SD 0.7) for females — women were ~24% more sensitive (p < 0.01).

Ghose et al. (Br J Clin Pharmacol 1976;3:334–337)¹⁶ found the same direction in 4 men and 6 women given IV tyramine under desmethylimipramine (a tricyclic antidepressant, different mechanism from MAOIs) or placebo: under placebo, men required 6.5 mg versus 4.7 mg for women (p < 0.10); under active drug 18.0 mg versus 10.2 mg (p < 0.05).

Practical implication: neither study involved MAO inhibitors or oral tyramine, so extrapolation to the linezolid context is uncertain. If the ~24% sex difference carries over, women on linezolid would have an effective oral PD30 closer to ~75–80 mg rather than the ~100 mg established in male subjects — narrowing the margin of safety before the "Safe on AB" ceiling is approached. Women should treat the "Safe on AB" column with more caution than men, and the high-variability foods (aged cheeses, cured meats, fermented items at the "Maybe" borderline) deserve particular attention.

The tables

Each table lists tyramine in milligrams per kilogram (mg/kg), which is the same as µg/g, and is how the food-chemistry literature reports it. For a sense of scale, 1 oz ≈ 28 g, so a 1 oz slice of cheese at 250 mg/kg delivers about 7 mg of tyramine — already over the MAOI ceiling.

The three Safe columns estimate whether a typical serving (1 oz cheese, 1 oz cured meat, 1 tbsp sauce or paste, 12 oz beer, 5 oz wine, 4 oz sauerkraut) is okay for three different situations, each with its own per-meal tyramine ceiling:

• Safe old MAOI. 6 mg/meal limit. — classic irreversible MAOIs (phenelzine, tranylcypromine, isocarboxazid). Ceiling ~6 mg/meal.
• Safe new MAOI. 50 mg/meal limit. — third-generation / reversible MAOIs and higher-dose transdermal selegiline.
• Safe on AB. 100 mg/meal limit. — the antibiotic linezolid (and furazolidone).

Because almost nobody eats exactly one bite, I've kept a ~3× margin of safety in each column:

• Yes — three servings still fit under that column's ceiling (roughly < 2 / < 17 / < 33 mg per serving).
• Maybe — one serving is usually fine, but more than one approaches the ceiling, or the food is variable enough that a bad batch could exceed it (roughly 2–6 / 17–50 / 33–100 mg per serving).
• No — one serving alone can blow past the ceiling (roughly > 6 / > 50 / > 100 mg per serving).

Note that the 100 mg ceiling for linezolid was established in fasted healthy males. You may be different:

• Higher BMI: If you have a higher BMI the limit may be ~4.6% higher per BMI point, but we don't know the BMI baseline or the shape of this curve. Plausibly the limit may be lower if your BMI is lower.
• Not fasting: If you are not fasting, the limits may be 2x higher (based on bioavailability) to 2.8x higher (based on a drug with similar MAO effects). This suggests that the meal to be most cautious about is breakfast.
• Woman: No tyramine--linezolid interaction study has been done on women, but studies on tyramine alone suggest the limit is about 24% lower.
• Pre-existing high blood pressure: No studies have been done for you, but you should be more cautious.

Remember, a high mg/kg number is harmless if you eat very little (soy sauce, yeast extract by the teaspoon), while a moderate number eaten in quantity (cheese, sauerkraut) can still get you. The Safe columns account for serving size; the mg/kg column does not.

Cheese

Aged cheese is the single most important high-tyramine food, and tyramine can't be guessed from taste, smell, or variety — it tracks aging and protein breakdown. The same cheese name spans orders of magnitude depending on how it was made and how long it sat; a 2024 systematic review found cheese tyramine ranging from 3.2 to 1,398 mg/kg¹⁷.

The reassuring news, per Gillman²⁴: most commercial, low-priced, supermarket cheeses now run 0–50 mg/kg, and even mature Parmigiano and Cheddar usually come in under 150 mg/kg. A 25–50 g portion of those typically delivers ~12 mg or less — so freshness and provenance matter more than the variety name.

Cured and fermented meats

Fresh and frozen meat is safe. The risk is entirely in aging, curing, fermenting, and spoilage — and, as with cheese, modern starter cultures have pulled most commercial salami down to ~5 mg per portion.

Fermented fish, dried fish, and fish sauce

This category contains the single highest values measured in any food.

Fermented soy products and sauces

Unfermented soy (tofu, soy milk) is inherently very low. Fermentation is what creates the problem — and the variability is wild enough that clinicians often just tell MAOI patients to skip all soybean products²⁸.

Sauerkraut and fermented vegetables

Plant fermentation generally carries less tyramine than animal-protein fermentation — except when seafood is added (as in kimchi).

Yeast extracts (Marmite, Vegemite, brewer's yeast)

Beer and wine

The consensus: bottled beer and wine in moderation are fine on an MAOI; tap and craft beer are the ones to avoid. In one survey only 4 of 98 beers exceeded 10 mg/L — but those reached 26–113 mg/L⁷.

Foods once restricted, now considered fine

A lot of the old MAOI handouts banned foods that simply don't contain meaningful tyramine. These are back on the menu:

Milk and non-cheese dairy

Fresh dairy carries almost no tyramine; only deliberately fermented milks creep up. Serving assumed: 1 cup (~250 g).

Fruits

Most fresh fruit has little or no tyramine. Serving assumed: 1 medium fruit (~120 g). (Banana, avocado, and raspberries appear in the "once restricted" table above.)

Vegetables (non-fermented)

Fresh vegetables are low in tyramine; several alarming numbers in old lists are 1970s analytical artifacts that modern assays don't reproduce, so the modern value is shown and the old one noted. Serving assumed: ~100 g.

Coffee, chocolate, and miscellaneous

Practical takeaways

1. Aging is the enemy. The single best predictor of tyramine is how much bacterial protein breakdown a food has been through. Fresh = safe; aged, cured, fermented, or spoiled = risky. When in doubt, ask "how long has this been sitting around?"
2. The real avoid-list is short. For a classic MAOI: aged and blue cheeses, concentrated yeast extracts, fermented soy pastes and sauces, sauerkraut/kimchi, fermented and dried fish, fava-bean pods, tap/craft beer, and anything spoiled or improperly stored. That's basically it.
3. Freshness beats blanket bans. Fresh and frozen meat, poultry, and fish; fresh dairy (cottage, cream, ricotta, milk, yogurt); non-fermented tofu and soy milk; eggs; most produce; and bottled beer/wine in moderation are all fine. Eat leftovers within ~48 hours and never thaw protein at room temperature.
4. Concentration isn't dose. A teaspoon of Marmite (~2 mg) is fine; a wedge of blue cheese (~28 mg/oz) is not. Always think in servings, not mg/kg.
5. Old numbers overstate today's risk. Modern hygiene and starter cultures have slashed tyramine in commercial cheese, salami, soy sauce, and beer. The scary figures in legacy lists are largely historical.
6. It's about the drug, not the diagnosis. The people who need this list are anyone whose MAO enzyme is blocked: classic MAOI antidepressants are the main case, but the antibiotic linezolid counts too — and a short antibiotic course is exactly when nobody's thinking about cheese. Low-dose transdermal selegiline, moclobemide, and tedizolid generally need no restriction. If your MAO isn't inhibited by something, this whole table is trivia.

Caveats

• Wide variability is the dominant theme. Tyramine content is intrinsically high-variance — the same cheese or sausage name can span two orders of magnitude depending on aging, starter cultures, storage, and spoilage. Published values span orders of magnitude across products, countries, decades, and lab methods. Treat any single mg/kg number as a point on a wide distribution, not a fixed value; the ranges matter more than the digits.
• Each Safe column assumes a different drug. Safe old MAOI uses the strict ~6 mg classic-MAOI ceiling; Safe new MAOI the ~50 mg third-generation/reversible ceiling; Safe on AB the ~100 mg linezolid ceiling. Read across to the column that matches your situation. If your MAO isn't inhibited at all, every column is effectively "Yes" — the healthy-person ceiling is ~600 mg.
• Per-serving figures are computed from each row's mg/kg value (1 oz = 28.35 g, 1 tbsp ≈ 15 g, 4 oz ≈ 113 g sauerkraut, 5 oz ≈ 148 mL wine, 12 oz ≈ 355 mL beer), so they're approximate and inherit the wide spread of the concentration ranges. Two values still come from a pharmaceutical patient guide (ZEPOSIA) — the pepperoni concentration and the bottled/draft-beer figures — which targets a different, higher threshold for a different drug.
• Fava beans are the odd one out. The fava-bean reaction is caused by levodopa/dopamine, not tyramine — a mechanistic distinction the old food lists tend to blur.
• This is a reference compilation, not medical advice. Anyone on an MAOI should follow their prescriber's and dietitian's specific guidance, and ideally keep a home blood-pressure log in the first weeks.

AI Notes

I used Claude extensively in generating this article. I have confidence in the results because:

• I've read the whole article, obviously.
• I acquired primary sources so numbers could be verified rather than vibed.
• I had Claude use visual PDF parsing in addition to pdftotext for data extraction.
• I had Claude add unit tests to the blog for the tables' "Safe?" columns and to check all the tables' unit conversions.
• I've had Claude double-check the numbers and broad conclusions several times without access to memory.
• I've spot-checked the tables myself.
• For the linezolid work that motivated this article, an existing literature, included here, matches my conclusions.
• The numbers of each food seem to me to be mechanistically coherent: foods that we expect would have higher tyramine content based on mechanism do. Fava beans are weird.

Sources