In Canada, tryptophan is sold as a prescription drug to treat mood disorders (such as bipolar disorder, depression). It is usually used with other medicines. It works to make the mood more stable and reduce extremes in behavior by restoring the balance of certain natural substances (serotonin, melatonin) in the brain. Tryptophan is a natural substance (amino acid) found in high-protein foods and milk.

In the US, tryptophan is sold as a dietary supplement. It has been used to support mood, relaxation, and restful sleep. If you are taking other medications that may affect serotonin (such as many antidepressants), do not take tryptophan without talking with your doctor first. A very serious (possibly fatal) drug interaction may occur. Your doctor should closely monitor you. See also Side Effects section.

Some supplement products have been found to contain possibly harmful impurities/additives. Check with your pharmacist for more details about the brand you use.

The US FDA has not reviewed this product for safety or effectiveness. Consult your doctor or pharmacist for more details.

If your doctor has prescribed this medication, take it by mouth with a meal or snack as directed by your doctor, usually 3 to 4 times a day. Taking this medication with food helps reduce side effects such as nausea.

Dosage is based on your medical condition and response to treatment. Your doctor may adjust your dose to find the best dose for you. Do not take this medication more often, increase your dose, or stop taking it without first consulting your doctor. Your condition will not improve faster and your risk of side effects will increase.

If your doctor has prescribed this medication, use it regularly to get the most benefit from it. To help you remember, take it at the same times each day.

If you are using tryptophan as a dietary supplement, take this product by mouth as directed. Follow all directions on the product package. If you have any questions, ask your doctor or pharmacist.

Consult your doctor or pharmacist before using this product for any mental/mood disorders such as depression or bipolar disorder. Your condition may require medical attention or prescribed medication.

Tell your doctor if your condition lasts or gets worse. If you think you may have a serious medical problem, get medical help right away.

Nausea, loss of appetite, dizziness, drowsiness, headache, or dry mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

If your doctor has prescribed this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• muscle stiffness/spasms
• severe muscle aches/pain
• unusual/inappropriate sexual urges
• shakiness (tremor)
• unusual weakness

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms:

• fast heartbeat
• hallucinations
• loss of coordination
• severe dizziness
• severe nausea/vomiting/diarrhea
• twitching muscles
• unexplained fever
• unusual agitation/restlessness

A very serious allergic reaction to this product is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking tryptophan, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• a certain muscle reaction to tryptophan (eosinophilia-myalgia syndrome)
• personal/family history of diabetes
• digestive problems (such as achlorhydria, malabsorption)
• low-protein diet
• scleroderma

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

A product that may interact with this drug is:

• sodium oxybate

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: seizures, loss of consciousness.

Do not share this medication with others. Keep all medical and lab appointments.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Different brands of this medication have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.