L-tryptophan

Pronunciation:

L TRIP toh fan

What is the most important information I should know about L-tryptophan?

L-tryptophan is sold as a dietary supplement and is not subject to U.S. Food and Drug Administration (FDA) guidelines for safe manufacturing. Some of the L-tryptophan sold in the U.S. is imported from manufacturers in other countries. The FDA has not determined the safety, purity, or effectiveness of L-tryptophan. All of the potential risks and benefits of using this product are therefore unknown.

Dietary supplements and herbal "medicines" may contain toxic or impure ingredients that could be harmful to your health. Dietary and herbal supplements should be purchased from a reliable source such as a pharmacy or well-known retail store. Do not use any dietary or herbal product that does not list a manufacturer and/or distributor name and address on the label.

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. Stop using L-tryptophan and call your doctor or care practitioner at once if you have any of these signs of EMS: 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; uneven heartbeat.

Less serious side effects are more likely to occur. Talk to your doctor or care practitioner about any side effect that seems unusual or that is especially bothersome.

Other drugs may interact with L-tryptophan. Tell your doctor or care practitioner about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor or care practitioner.

Stop using L-tryptophan and get emergency medical help if you think you have used too much of the product, or if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

What is L-tryptophan?

The use of dietary or herbal supplements in cultural and traditional settings may differ from what is accepted in Western medicine. When considering the use of any dietary or herbal supplement, it is best to talk with your medical doctor. You may also talk with a naturopathic doctor or other practitioner trained in the use of herbal medicines.

L-tryptophan is an amino acid that is made from plant or animal sources. It has been used to treat sleep problems (insomnia), anxiety, depression, premenstrual syndrome, attention deficit disorder, and for smoking cessation and other conditions. L-tryptophan may also be used for purposes other than those listed here.

What should I discuss with my health care provider before taking L-tryptophan?

Before taking L-tryptophan, tell your doctor or other care practitioner if you have:

liver disease;
kidney disease;
eosinophilia; or
a muscle disorder (such as fibromyalgia).

If you have any of the conditions listed above, you may not be able to use L-tryptophan, or you may need a dosage adjustment or special tests during treatment.

Do not use L-tryptophan without telling your doctor or care practitioner if you are pregnant. It is not known whether L-tryptophan would be harmful to an unborn baby.

Do not use L-tryptophan without telling your doctor or care practitioner if you are breast-feeding a baby. It is not known whether L-tryptophan would be harmful to a nursing infant.

How should I take L-tryptophan?

Take L-tryptophan exactly as directed on the label, or as your doctor or care practitioner has prescribed it for you. Do not use more of the product than recommended, and do not use it for longer than recommended.

Do not give any herbal/health supplement to a child without first talking to the child's doctor.

Store L-tryptophan at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the next regularly scheduled. Do not take extra L-tryptophan to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this product.

What should I avoid while taking L-tryptophan?

L-tryptophan can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid using other dietary or herbal supplements to treat the same condition for which you are using L-tryptophan.

What are the possible side effects of L-tryptophan?

Stop using L-tryptophan and 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.

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.

Other less serious side effects are more likely to occur. Talk with your doctor or care practitioner if you have any of these less serious side effects:

dry mouth, heartburn, burping, gas;
nausea, vomiting, diarrhea;
feeling drowsy or light-headed;
blurred vision;
weakness, lack of coordination;
headache; or
lost appetite.

Side effects other than those listed here may also occur. Talk to your doctor or care practitioner about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect L-tryptophan?

L-tryptophan may interact with other medicines. Before taking L-tryptophan, tell your doctor or care practitioner if you are also using:

medicine for depression such as St. John's wort, citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), amitriptyline (Elavil), imipramine (Tofranil), venlafaxine (Effexor), and others;
a monoamine oxidase inhibitor (MAOI) such as tranylcypromine (Nardil), phenelzine (Parnate), selegiline (Eldepryl), or isocarboxazid (Marplan);
a sedative or tranquilizer such as diazepam (Valium), lorazepam (Ativan), clonazepam (Klonipin) and others;
a phenothiazine drug such as chlorpromazine, (Thorazine), prochlorperazine (Compazine) and others; or
drugs that make you sleepy (such as alcohol, cold medicine, pain medication, muscle relaxants, and medicine for depression or anxiety).

If you are using any of these drugs, you may not be able to take L-tryptophan, or you may need dosage adjustments or special tests during treatment.

There may be other drugs not listed that can affect L-tryptophan. Tell your doctor or care practitioner about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor or care practitioner.

Where can I get more information?

Your pharmacist has more information about L-tryptophan written for health professionals that you may read.

What does my medication look like?

L-tryptophan is available over-the-counter (without a prescription) under. Many different brand or generic forms may be available. Ask your pharmacist any questions you have about this product, especially if it is new to you.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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