L-tryptophan is an amino acid that is made from plant or animal sources.
L-tryptophan has been used in alternative medicine as an aid to treat sleep problems (insomnia), anxiety, depression, premenstrual syndrome, attention deficit disorder, and for smoking cessation and other conditions.
Not all uses for l-tryptophan have been approved by the FDA. L-tryptophan should not be substituted for medications prescribed for you by your doctor.
L-tryptophan is often sold as an herbal supplement. There are no regulated manufacturing standards in place for many herbal compounds and some marketed supplements have been found to be contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.
It is dangerous to try and purchase l-tryptophan on the Internet or from vendors outside of the United States. The sale and distribution of l-tryptophan outside of the U.S. does not comply with the regulations of the Food and Drug Administration (FDA) for the safe use of this medication.
L-tryptophan may also be used for other purposes not listed in this product guide.
When considering the use of herbal supplements, seek the advice of your doctor. You may also consider consulting a practitioner who is trained in the use of herbal/health supplements.
If you choose to take l-tryptophan, use it as directed on the package or as directed by your doctor, pharmacist, or other healthcare provider. Do not use more of l-tryptophan than is recommended on the label.
Take the medicine as prescribed by your doctor.
Take 1 or 2 capsules daily. For optimum absorption, take separately from protein-containing foods and dietary supplements containing protein or amino acids.
Store L-tryptophan at room temperature away from moisture and heat.
L-tryptophan is a protein building block that can be found in many plant and animal proteins.
Do not use this product if you are allergic to l-tryptophan.
Before using l-tryptophan, talk to your doctor, pharmacist, herbalist, or other healthcare provider. You may not be able to use l-tryptophan if you have certain medical conditions.
If you have certain conditions, you may need a dose adjustment or special tests to safely use this product. Before using l-tryptophan, talk to your doctor, pharmacist, herbalist, or other healthcare provider if you have:
eosinophilia (high levels of a certain type of white blood cells); or
a muscle disorder (such as fibromyalgia).
It is not known whether l-tryptophan is harmful to an unborn baby. Do not use this product without talking to a healthcare provider if you are pregnant or plan to become pregnant during treatment. L-tryptophan may pass into breast milk and may harm a nursing baby. Ask your healthcare provider before using l-tryptophan if you are breast-feeding a baby. Do not give any herbal/health supplement to a child without the advice of a doctor.
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
In 1989, a life-threatening condition called eosinophilia-myalgia syndrome (EMS) occurred in many people using L-tryptophan and some died from the condition. All of these people had taken L-tryptophan distributed by a company in Japan. This L-tryptophan was found to contain trace levels of impure ingredients. Since that time, the FDA has limited the availability of L-tryptophan in the U.S. However, the increased use of the Internet has made many dietary supplements available from non-U.S. sources.
There have been no published cases of EMS within the last several years, but you should be aware of the symptoms. Call your doctor at once if you have any of the following:
severe muscle pain (most often in the shoulders, back, or legs);
weakness, numbness, tingling, or burning pain (especially at night);
tremors or twitching muscle movements;
swelling in any part of your body;
skin changes (dryness, yellowing, hardening);
breathing difficulty; or uneven heartbeat.
Less serious side effects may include:
dry mouth, heartburn, burping, gas;
nausea, vomiting, diarrhea;
feeling drowsy or light-headed;
weakness, lack of coordination;
headache; or lost appetite.
This is not a complete list of side effects and others may occur.
Call your doctor for medical advice about side effects.