Lysine
What it is and what it does
- Lysine is one of the nine essential amino acids, along with the others listed by MedlinePlus. (MedlinePlus Medical Encyclopedia (US National Library of Medicine): Amino acids (review date 1/21/2025))
- Like threonine, lysine does not take part in transamination, so the body cannot make it from its keto acid. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- Lysine makes up about 6-8% of most proteins. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- Lysine in collagen - the main structural protein of skin and connective tissue - is converted to hydroxylysine. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- Lysine and hydroxylysine form cross-links between collagen molecules; this cross-linking is essential for collagen's mechanical properties and for bone mineralisation. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- The body starts making carnitine from lysine units in proteins, mainly muscle proteins. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
Why it matters
- Symptoms of lysine deficiency include poor appetite, weight loss in adults, delayed growth in children, anaemia, tiredness and mood changes. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- WHO/FAO/UNU (2007) calculated that the average Indian diet (mean of 17 states) supplies lysine at 87% of the requirement level, i.e. below it. (WHO/FAO/UNU (2007). Protein and amino acid requirements in human nutrition: report of a joint FAO/WHO/UNU expert consultation. WHO Technical Report Series 935)
- High lysine intakes, mainly as lysine hydrochloride supplements, most often cause stomach and gut upsets such as nausea. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- A 2025 review reports that 6 g lysine a day was the long-term dose with no observed adverse effect (NOAEL) in humans. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
General information, not medical advice — for your own needs, ask a doctor or dietitian.
How much is needed
| Who | Amount | What the figure is | Whose figure |
|---|---|---|---|
| Adults | 45 mg per g protein | Recommended amino acid pattern (ICMR-NIN 2020) | ICMR-NIN 2020 (as printed in DGI 2024 Table 8.2) |
| Adults (mean requirement) | 30 mg/kg body weight/day | Average requirement | FAO/WHO/UNU 2007 (not an Indian value) |
| Older children, adolescents and adults | 48 mg per g protein | Scoring pattern for protein quality | FAO 2013 (not an Indian value) |
India’s own figure (ICMR-NIN 2020) comes first. Figures from other bodies are shown only where they help, and say whose they are.
Sources: ICMR-NIN. Dietary Guidelines for Indians 2024; WHO/FAO/UNU (2007). Protein and amino acid requirements in human nutrition: report of a joint FAO/WHO/UNU expert consultation. WHO Technical Report Series 935; FAO (2013). Dietary protein quality evaluation in human nutrition: report of an FAO Expert Consultation. FAO Food and Nutrition Paper 92
In every millet and pseudo-cereal, per 100 g raw
| Grain | Amount | Source |
|---|---|---|
| Quinoa | 5.55 g per 100 g protein | IFCT A009 |
| Rajgira (amaranth) | 5.5 g per 100 g protein | IFCT A002 |
| Bajra (pearl millet) | 3.19 g per 100 g protein | IFCT A003 |
| Ragi (finger millet) | 2.83 g per 100 g protein | IFCT A010 |
| Little millet | 2.42 g per 100 g protein | IFCT A016 |
| Jowar (sorghum) | 2.31 g per 100 g protein | IFCT A005 |
| Kodo millet | 1.42 g per 100 g protein | IFCT A017 |
| Kuttu (buckwheat) | 0.672 g | USDA FDC 170286 |
| Teff | 0.376 g | USDA FDC 169747 |
| Proso millet | 0.212 g | USDA FDC 169702 |
Each grain has ONE source, named on its page: IFCT = Indian Food Composition Tables 2017 (ICMR-NIN) with its food code; USDA FDC; FAO WAFCT 2019; NIN 2007 via ICAR-IIMR. Values exactly as printed, not converted — tables differ in method, so compare within a source. Published values for the grain, not a laboratory test of our packs.
Absorption and food
- Cooking pulses for too long lowers their nutritive value because lysine is lost. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- At high temperatures lysine reacts with carbonyl compounds (the Maillard reaction), forming glycated lysine, which the body may not be able to use. (Holecek M. Lysine: Sources, Metabolism, Physiological Importance, and Use as a Supplement. Int J Mol Sci 2025;26(18):8791. doi:10.3390/ijms26188791 (open access, CC BY))
- When quinoa is dry-roasted (toasted), reducing sugars cause browning through the Maillard reaction, and the lysine affected is no longer biologically useful. (FAO (2011). Quinoa: An ancient crop to contribute to world food security (aq287e))
- Pulses have more lysine, and less of the sulphur amino acids methionine and cysteine, than cereals (ICMR-NIN). (ICMR-NIN. Dietary Guidelines for Indians 2024)
- ICMR-NIN's model vegetarian diet ('My Plate for the Day') provides 49.0 mg lysine per g of protein, more than the 45 mg/g recommendation. (ICMR-NIN. Dietary Guidelines for Indians 2024)
- Quinoa protein has been reported to contain 5.6 g lysine per 16 g nitrogen, compared with 3.2 g in rice and 2.8 g in wheat. (FAO (2011). Quinoa: An ancient crop to contribute to world food security (aq287e))