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SEPHIENCE™ Dosing Calculator

Quickly determine the appropriate once-daily oral dose of SEPHIENCE based on your patient’s age and weight

Age Recommended Starting Dose†,‡
<6 months 7.5 mg/kg/day
6 to <12 months 15 mg/kg/day
12 months to <2 years 30 mg/kg/day
≥2 years 60 mg/kg/day§

† For calculated daily doses less than 1000 mg, the final concentration of prepared SEPHIENCE liquid mixture is 25 mg/mL.

‡ 60 mg/kg is the maximum daily dose for all patients.

§ For patients ≥2 years of age, the recommended starting dose and maximum dose is 60 mg/kg.

To support appropriate blood Phe levels, adjust SEPHIENCE dosage and/or dietary protein and Phe intake.

SEPHIENCE dosage may be titrated incrementally based on blood Phe levels, up to a maximum of 60 mg/kg/day.

Let’s begin!

SEPHIENCE is dosed based on the patient’s age and weight.

Please enter your patient’s age and weight in the sections below to determine the appropriate SEPHIENCE dose.

Patient Age
kg Patient Weight
mg Total Dose Per Day
mL or Tbsp
Administered Dose Volume Per Day
x 1000-mg Sachet(s) and x 250-mg Sachet(s)
Total Daily SEPHIENCE

The above calculator is provided as a guide for help calculating your patient’s dose (for Canadian healthcare professionals only). The information provided is not intended to supersede independent clinical judgment, and calculations should be confirmed.

Made to Mix into Daily Routines—Available in 250-mg and 1000-mg Sachets

1

PREPARE

  • Use individual SEPHIENCE sachets (250 mg or 1000 mg).
  • Mix the powder with water or apple juice.§
    • For daily doses <1000 mg, prepare each 250-mg SEPHIENCE sachet with 9 mL of water or apple juice.
    • For doses ≥1000 mg, prepare each 1000-mg sachet with 30 mL of liquid or soft food (e.g., applesauce or strawberry jam), and add an additional 30 mL for up to three 250-mg sachets.
§ Patients younger than 6 months of age should use only water when mixing SEPHIENCE.
2

MIX

  • Stir liquids for at least 30 seconds.
  • Stir soft foods for at least 60 seconds.
  • Mix until uniform. Some powder may remain visible — this is normal.
3

ADMINISTER

  • Instruct your patient to consume the mixture immediately using an oral syringe or cup to ensure accurate dosing.
4

RINSE

  • Rinse the syringe or cup with water or juice, and instruct your patient to swallow immediately to ensure the full dose is taken. Repeat if particles remain.
5

DELAYED ADMINISTRATION

If not taken right away:

  • Cover and store at room temperature (20 °C to 25 °C) for up to 6 hours, or
  • Refrigerate (2 °C to 8 °C) for up to 24 hours.

Stir again before use:

  • ≥30 seconds for liquids
  • ≥60 seconds for soft foods

Missed dose? Instruct your patient to:

Take as soon as remembered.
Never double dose on the same day.
dosing and administration guide
Additional Resources

SEPHIENCE Dosing and Administration Guide

Key information on dosing and administration to help healthcare professionals incorporate SEPHIENCE into patients’ treatment plans.

Download

SEPHIENCE™ (sepiapterin for oral suspension) is indicated for the treatment of hyperphenylalaninemia (HPA) in adult and pediatric patients 1 month of age and older with sepiapterin-responsive phenylketonuria (PKU). SEPHIENCE is indicated in conjunction with a phenylalanine (Phe)-restricted diet.

Please consult the Product Monograph at SEPHIENCEPM.ca/EN for contraindications, warnings, precautions, adverse reactions, interactions, dosing, and conditions of clinical use. The Product Monograph is also available by calling PTC Therapeutics Canada Medical Information at 1-866-899-7002 or emailing camedinfo@ptcbio.com.

* By accessing or using such identified information or services on this Site, you are acknowledging that you are a licensed Canadian healthcare professional, and you confirm that your licence is current and in good standing.

Reference: SEPHIENCE™ (sepiapterin for oral suspension) Product Monograph. PTC Therapeutics. October 7, 2025.