Know your Amino Acids fact sheet:
| Full name | Cysteine |
| 3 letter name | Cys |
| 1 letter name | C |
| What you see: | What a biochemist sees: |
 |
 |
| Speciality | – |
| Sources (animal) | meat, chicken, turkey, duck, eggs, milk products |
| Sources (plant) | red peppers, garlic, onions, broccoli, brussels sprout, oats, granola, wheat germ, sprouted lentils |
| Chemical formula | C3H7NO2S |
| Essential | – |
| Non-essential | X |
| Hydrophobic | – |
| Hydrophilic (neutral) | X |
| (positive) | – |
| (negative) | – |