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I pulled up our own lettuce microgreens page last week to check a single number, and the number was wrong. Not slightly wrong. The nutrition table on it was the USDA record for a full-grown head of green leaf lettuce, printed under a heading that said microgreens.
That is an easy mistake to make and a hard one to catch. No USDA entry exists for a lettuce seedling, so somebody reaches for the nearest thing on the shelf, and the label quietly stops matching the food.
So the page has been rebuilt from the studies up. What follows is what has been measured in a lettuce microgreen, what has not, and how to tell those two apart.
Key takeaway
Lettuce microgreens are the seedling stage of Lactuca sativa, cut about two weeks after sowing. In the one trial that grew seedlings and full heads in the same soil, on the same farm, in the same winter, the seedlings carried roughly a quarter of the nitrate and led on six minerals while trailing on three (Pinto et al., 2015).
Below: what the seedling actually is, what has been measured in it, how it stacks up against the lettuce already in your fridge, what it is good for, and how to keep it from turning to mush by Thursday.
The lettuce evidence page
Every number on this page, plus the ones that did not survive checking. Fifteen places where a published paper disagrees with its own table, the figures that had to be dropped because of it, and the six questions people ask at a market table, all in one place.
What are lettuce microgreens?
The clip above is the lettuce section of a three-crop time lapse, seed to open cotyledons in about a minute.
A lettuce microgreen is the same plant that becomes a head of lettuce, cut roughly ten to eighteen days after sowing, when the two seed leaves have opened and the first true leaf is just showing. Growers cut above the growing medium, so the root and the medium stay in the tray.
You will see them sold as micro lettuce, microgreen lettuce, or micro salad leaves. Same thing.
What you notice first is what is missing. No pepper, no heat, none of the bite that radish or mustard brings. They are mild and faintly sweet, and soft enough to disappear into a sandwich without announcing themselves. That makes lettuce microgreens the one to put in front of somebody who tried radish microgreens once and never went back.
The plant is small in a way that is easy to underestimate. In the Portuguese trial, a single seedling weighed 1.96 grams. A mature head from those same three fields weighed 176 grams (Pinto et al., 2015).
They are also mostly water, and the numbers say so plainly. Dry matter measured 7.53 percent across eleven varieties in Spain and 5.2 percent in Portugal (Martínez-Ispizua et al., 2022; Pinto et al., 2015). Two laboratories, two countries, two substrates, and the same answer within a couple of points.
What is actually in lettuce microgreens?
Less than most nutrition tables would have you believe, and this is where the old version of this page went wrong. There is no USDA FoodData Central entry for a lettuce seedling. The entry that exists is for mature green leaf lettuce, and it is a genuinely useful reference so long as nobody relabels it.
Here it is, honestly labelled, per 100 grams, with percentages recomputed against the FDA Daily Values in 21 CFR 101.9 rather than the NIH intake figures the old table used.
Table 1. Mature green leaf lettuce, raw. USDA FoodData Central. Per 100 g. This is the full-grown leaf, not the seedling.
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Vitamin K | 126 µg | 105% |
| Vitamin A, RAE | 370 µg | 41% |
| Lutein + zeaxanthin | 1,730 µg | 29% |
| Manganese | 0.25 mg | 11% |
| Vitamin C | 9.2 mg | 10% |
| Folate | 38 µg | 10% |
| Riboflavin | 0.08 mg | 6% |
| Vitamin B-6 | 0.09 mg | 5% |
| Iron | 0.86 mg | 5% |
| Fibre | 1.3 g | 5% |
| Potassium | 194 mg | 4% |
| Calcium | 36 mg | 3% |
| Energy | 15 kcal |
Now the seedling. This is the short list, because it is all anybody has published.
Table 2. Measured in lettuce microgreens. Growing conditions attached, because they move the numbers.
| Measured | Value | Where |
|---|---|---|
| Dry matter | 7.53% | 11 varieties, coir, Valencia (Martínez-Ispizua et al., 2022) |
| Nitrate | 503 mg/kg fresh weight | cv. ‘Grand Rapids TBR’, peat, 18 days, Cyprus (Kyriacou et al., 2021) |
| Carotenoids | 3.70 µg/g, range 0 to 43.48 | same 11 varieties (Martínez-Ispizua et al., 2022) |
| Ascorbic acid | 61.05 mg/100 g | same 11 varieties, and read the caution below |
No published table carries a value for the two-week lettuce seedling on protein, fibre, energy, vitamin A, vitamin E, vitamin K, folate, or any B vitamin. Any fuller-looking table you meet for lettuce microgreens is borrowing from somewhere, and the usual lender is the mature head.
Are lettuce microgreens more nutritious than regular lettuce?
Sometimes yes, sometimes no. The honest answer needs that word in it.
Almost every microgreen-versus-mature comparison sets one laboratory’s seedling against a database entry for somebody else’s mature crop. Lettuce is one of the very few crops where that shortcut was not needed.
A team at the University of Porto grew lettuce across three greenhouse fields in northern Portugal through one winter, cutting seedlings at two weeks and heads at ten, both from the same soil. The seedlings led on calcium, iron, manganese, zinc, selenium and molybdenum. The heads led on nitrogen, phosphorus and potassium. The seedlings carried roughly a quarter of the nitrate (Pinto et al., 2015).
Not “more nutritious”, and not a number you can put on a label.
A Spanish team measured eleven lettuce varieties at three growth stages. Ascorbic acid fell steadily from seedling to adult. Carotenoids ran the other way, peaking at the baby stage, with seedlings averaging 3.70 µg/g and some trays reading zero (Martínez-Ispizua et al., 2022). A second laboratory found the same pattern (Mallor et al., 2023).
One caution on that vitamin C figure. That trial’s own adult lettuce read 34.45 mg per 100 g against a USDA reference of 9.2, so the laboratory’s whole scale sits high. The direction is solid. The magnitude belongs to that laboratory.
If you sell lettuce microgreens and need the whole measured record with the statistical letters, the lettuce entry in our Variety Library carries it.
What are lettuce microgreens good for?
Eating. That is the honest headline, and it is a better answer than it sounds.
Lettuce microgreens are the mildest thing on the microgreen table. They go on at the end, never into a pan, and they soften a plate that already has something sharp on it. A handful on a sandwich, a scatter over a bowl. They are the microgreen a child will actually eat.
On nutrition, what can be said is what Table 2 says: they carry less nitrate than a mature head grown in the same soil, they are mostly water, and their carotenoid content is low and inconsistent.
What cannot be said is the part worth being clear about. There is no published human trial on eating lettuce microgreens. None, in any journal. The only human feeding trial on microgreens of any species used red beet and red cabbage, ran for two weeks with 24 people, and found no change in blood pressure, no change in arterial measures, and no change in gut microbiome diversity (Lee et al., 2025). The authors’ own conclusion is that future studies designed to evaluate health impacts are needed.
So everything above is a measurement of what sits inside a plant. None of it is evidence about what happens in a body.
This information is educational and is not a substitute for professional medical advice. Talk with your physician before making significant changes to your diet or before using microgreens to address a health concern.
How do you grow and keep lettuce microgreens?
Lettuce is a forgiving crop to grow and an unforgiving one to keep, and most people get that backwards.
Growing is straightforward. Lettuce microgreens go into a shallow tray of coir or peat, get light rather than a dark stacking period, and come off between ten and eighteen days. Once the first true leaf opens, the window is closing.
Keeping them alive after the cut is the hard part, and there is one published storage trial to go on. An Indian team stored lettuce and mustard microgreens in vented boxes at 5 degrees and scored them every three days. Uncoated lettuce stopped being saleable on day three. With an aloe vera gel coating it reached day six. Mustard, in the same boxes, reached day nine (Sobhanan et al., 2025).
Three days is the number to plan around. Buy less, more often. Keep them cold and dry, because water sitting on the leaf is what finishes them. Do not wash until you use them.
That is a single trial from one laboratory, on a cultivar the paper never named, and nobody has repeated it. Treat it as the shape of the problem rather than a promise.
Microgreens can also be grown deliberately low in potassium by adjusting the nutrient solution, a horticultural finding rather than a clinical one, which matters if you grow for someone with kidney disease (Renna et al., 2018).
Wrap-up: what is actually in lettuce microgreens
The short version is that lettuce microgreens are a mild, watery seedling with less nitrate than the mature head and a genuinely thin research file. That is less exciting than most pages on this subject will tell you, and it has the advantage of being checkable.
The reason this page could be rebuilt at all is that somebody grew both stages in one soil and measured them together. Most crops do not have that, which is why most microgreen comparisons quietly compare two different farms.
What is in a lettuce microgreen is one piece of a larger picture. If you want to see how every crop gets measured against the same standard of evidence, the Variety Library is where that work lives.
The lettuce evidence page
Every number on this page, plus the ones that did not survive checking. Fifteen places where a published paper disagrees with its own table, the figures that had to be dropped because of it, and the six questions people ask at a market table, all in one place.
Lettuce microgreens: frequently asked questions
Are lettuce microgreens safe to eat raw?
Yes. Two Canadian microgreens recalls for pathogenic E. coli happened in May 2026, both caught before anyone reported an illness. Seed is the usual way contamination gets in, not the tray, so the question worth asking a grower is where their seed comes from and how they handle water. Buy from someone who can answer it.
Can you use regular lettuce seed for microgreens?
Yes. Lettuce microgreens are the same species as head lettuce, so ordinary lettuce seed works. What changes is quantity, because you sow densely rather than spacing plants out, and cost per tray follows from that. Seed sold as microgreen seed is usually the same thing in a bigger bag, sometimes tested for pathogens.
What is the difference between microgreens and sprouts?
Sprouts are germinated in a jar, warm and wet and in the dark, then eaten whole with the root still attached. Those are also good conditions for bacteria, which is why sprouts carry the heavier food safety record of the two. Lettuce microgreens are never grown that way, and that one difference in method drives everything else.
Are romaine lettuce microgreens different from other types?
Less than the variety name suggests. Romaine, butterhead and loose-leaf all produce a mild, pale seedling, and at two weeks they resemble each other far more closely than their mature forms ever do. Choose on germination reliability and how evenly a variety fills a tray, not on which lettuce you happen to like at full size.
How much is one serving of lettuce microgreens?
About 20 grams, which is roughly what fits in a cupped hand. That matters because nutrient figures get published per 100 grams and almost nobody eats 100 grams in a sitting. At 20 grams, a figure that reads as 68 percent of a Daily Value lands nearer 14 percent. Publish the serving number.
Why is there no USDA entry for lettuce microgreens?
Because FoodData Central catalogues foods that are widely eaten and sampled, and lettuce seedlings are neither, yet. The database also carries no nitrate values for anything, which is why the strongest lettuce microgreen finding has no USDA counterpart to check it against. The gap is real and worth saying out loud.
References
Kyriacou, M. C., El-Nakhel, C., Soteriou, G. A., Graziani, G., Kyratzis, A., Antoniou, C., Ritieni, A., De Pascale, S., & Rouphael, Y. (2021). Preharvest nutrient deprivation reconfigures nitrate, mineral, and phytochemical content of microgreens. Foods, 10(6), 1333. https://doi.org/10.3390/foods10061333
Lee, S. Y., Michell, K. A., Butler, M. M., Smith, B. T., Woolf, E. K., Holmes, S. C., Grabos, L. E., Vazquez, A. R., Isweiri, H., Bunning, M., Uchanski, M. E., Rao, S., Newman, S. E., Weir, T. L., & Johnson, S. A. (2025). Feasibility and tolerability of daily microgreen consumption in healthy middle-aged/older adults: A randomized, open-label, controlled crossover trial. Nutrients, 17(3), 467. https://doi.org/10.3390/nu17030467
Mallor, C., Bertolín, J. R., Paracuellos, P., & Juan, T. (2023). Nutraceutical potential of leafy vegetables landraces at microgreen, baby, and adult stages of development. Foods, 12(17), 3173. https://doi.org/10.3390/foods12173173
Martínez-Ispizua, E., Calatayud, Á., Marsal, J. I., Cannata, C., Basile, F., Abdelkhalik, A., Soler, S., Valcárcel, J. V., & Martínez-Cuenca, M.-R. (2022). The nutritional quality potential of microgreens, baby leaves, and adult lettuce: An underexploited nutraceutical source. Foods, 11(3), 423. https://doi.org/10.3390/foods11030423
Pinto, E., Almeida, A. A., Aguiar, A. A., & Ferreira, I. M. P. L. V. O. (2015). Comparison between the mineral profile and nitrate content of microgreens and mature lettuces. Journal of Food Composition and Analysis, 37, 38–43. https://doi.org/10.1016/j.jfca.2014.06.018
Renna, M., Castellino, M., Leoni, B., Paradiso, V. M., & Santamaria, P. (2018). Microgreens production with low potassium content for patients with impaired kidney function. Nutrients, 10(6), 675. https://doi.org/10.3390/nu10060675
Sobhanan, A., Meena, R., Pareek, S., Meena, B., Mishra, G. P., & Koley, T. K. (2025). Aloe vera gel coating maintains quality and safety and extends shelf life of Brassica juncea L. and Lactuca sativa L. microgreens. Journal of Food Quality, 2025, 2441276. https://doi.org/10.1155/jfq/2441276
Xavier, I. B., Tavares, J. L., Pontes, E. D. S., Magnani, M., & Alvarenga, V. O. (2025). Understanding food safety on sprouts and microgreens: Contamination routes, outbreaks and challenges. Food Research International, 214, 116589. https://doi.org/10.1016/j.foodres.2025.116589
U.S. Department of Agriculture, Agricultural Research Service. FoodData Central: Lettuce, green leaf, raw. https://fdc.nal.usda.gov
U.S. Food and Drug Administration. 21 CFR 101.9, Nutrition labeling of food. Daily Values for adults and children four or more years of age.
