Apo-Tryptophan: Uses, Side Effects and Dosage

What is APO-TRYPTOPHAN used for?

APO-TRYPTOPHAN is used in addition to antidepressants to depressive disorders.

How does APO-TRYPTOPHAN work?

APO-TRYPTOPHAN contains L-Tryptophan, one of the eight essential amino acids. It works by increasing the level of serotonin (a neurotransmitter) in the central nervous system in the body.

What are the ingredients in APO-TRYPTOPHAN?

Medicinal ingredient: L-Tryptophan

Non-medicinal ingredients:

• Tablets: Croscarmellose sodium, magnesium stearate, methylcellulose and stearic acid.
• Capsules: Croscarmellose sodium, magnesium stearate, methylcellulose and stearic acid. The capsule shell contains gelatin and titanium dioxide. The edible black printing ink on the capsule shell contains colouring agent iron oxide black.

APO-TRYPTOPHAN comes in the following dosage forms:

• Capsules; 500 mg
• Tablets; 250 mg, 500 mg, 750 mg and 1 g

Do not use APO-TRYPTOPHAN if:

• you have a known allergy to APO-TRYPTOPHAN or to any of the other ingredients APO-TRYPTOPHAN contains.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take APO-TRYPTOPHAN. Talk about any health conditions or problems you may have, including if you:

• have ever had an allergic reaction (swelling, itching, rash, hives, and wheezing) to APO-TRYPTOPHAN or any of the inactive ingredients APO-TRYPTOPHAN contains
• have diabetes or have family history of diabetes

Other warnings you should know about:

• There have been rare cases of a condition called “serotonin syndrome” in patients taking APO-TRYPTOPHAN with other drugs that affect your serotonin levels. Symptoms may include involuntary muscle movements or spasms, tremors, agitation, and overactive reflexes. Talk to your healthcare professional if you notice any of these symptoms.
• Your doctor may prescribe you a vitamin B₆ supplement while you are taking APO-TRYPTOPHAN. This may help your body process (metabolize) APO-TRYPTOPHAN better.

• APO-TRYPTOPHAN may make you drowsy, or dizzy. Before driving a vehicle or doing activities that require alertness, wait to see how you feel after taking APO-TRYPTOPHAN.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with APO-TRYPTOPHAN:

• Lithium
• Monoamine oxidase inhibitors (e.g., moclobemide, phenelzine, tranylcypromine)
• Selective norepinephrine reuptake inhibitors (SNRIs; e.g., venlafaxine)
• Selective serotonin reuptake inhibitors (SSRIs; e.g., fluoxetine, fluvoxamine, paroxetine, sertraline)

How to take APO-TRYPTOPHAN:

Take APO-TRYPTOPHAN as directed by your healthcare professional. The usual recommended adult dose of APO-TRYPTOPHAN is 8 g to 12 g daily taken in 3 to 4 equally divided doses. Take with meals or snacks to help reduce nausea.

For better results APO-TRYPTOPHAN should be taken with a protein-low, carbohydrate rich meal.

Overdose:

If you think you, or a person you are caring for, have taken too much APO-TRYPTOPHAN, contact a healthcare professional, hospital emergency department, regional poison control centre or Health Canada’s toll-free number, 1-844 POISON-X (1-844-764-7669) immediately, even if there are no signs or symptoms.

Missed Dose:

If you forget to take a dose of APO-TRYPTOPHAN take it as soon as possible, then just carry on with the regular times you take your medication. If you remember your missed dose close to the time for your next dose, do not take the missed dose.

What are possible side effects from using APO-TRYPTOPHAN?

These are not all the possible side effects you may have when taking APO-TRYPTOPHAN. If you experience any side effects not listed here, tell your healthcare professional.

Side effects may be due to APO-TRYPTOPHAN or due to other drugs taken with APO-TRYPTOPHAN. Side effects may include:

• agitation
• confusion
• diarrhea
• disorientation
• drowsiness
• loss of appetite
• overactive reflexes
• poor coordination / concentration
• restlessness
• sexual disinhibition (unusual sexual behaviour)
• shivering
• sudden or involuntary moves or spasms (myoclonus)
• sweating
• talking or acting with excitement you cannot control
• trembling or shaking
• twitching
• vomiting

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting Side Effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

• Visiting the Web page on Adverse Reaction Reporting (canada.ca/drug-device-reporting) for information on how to report online, by mail or by fax; or
• Calling toll-free at 1-866-234-2345.

NOTE: Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.

Storage:

• Store in a well-closed container at controlled room temperature 15°C-30°C.
• Protect from light.
• Do not use APO-TRYPTOPHAN after the expiry date. All expired medications should be returned to your pharmacist.

Keep out of reach and sight of children.

If you want more information about APO-TRYPTOPHAN:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes this Patient Medication Information by visiting the Health Canada website: (https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-database.html); the manufacturer’s website (http://www.apotex.ca/products), or by calling 1-800-667-4708.

Last Revised: MAR 3, 2026