Phenylalanine can trigger allergic reactions, with symptoms such as:
Side effects may include:
Doses higher than 5,000 milligrams a day can cause nerve damage.
- Itching
- Swelling of the face or hands
- Trouble breathing
- Tingling feeling in the mouth
- Heartburn
- Fatigue
- Nausea
- Constipation
- Dizziness
- Headache
- Anxiety and hypomania (a milder form of mania)
- Sedation
- Jitteriness and trouble sleeping