Sometimes, you may notice changes in the formulation of your prescription medication, such as alterations to the added ingredients (e.g., glycine, B12, B6) or differences in the syringe volume for your prescribed dose. These changes are often related to variations in how partner pharmacies compound your medication. Below, we explain the potential reasons behind these changes and the roles of the different additive ingredients to help you better understand your prescription.
Why did my prescription change?
Partner pharmacy variations
Your medication may be fulfilled by different partner pharmacies. While all partner pharmacies meet quality and safety standards, each follows its own established compounding protocols and formulation practices.
For example, one pharmacy may include glycine as part of its established formulation protocol, while another may incorporate specific vitamins such as pyridoxine (vitamin B6) or a particular form of vitamin B12, such as methylcobalamin or cyanocobalamin. These variations reflect differences in compounding approaches rather than differences in therapeutic intent.
Adjustments in concentration and syringe volume
Compounding concentrations can differ between pharmacies, which might affect the syringe volume needed to achieve the same prescribed dose. For example:
A stronger concentration may reduce the required injection volume for the same dose in milligrams (mg). Conversely, a lower concentration might increase the injection volume or syringe units. Always refer to dose-specific instructions provided by the pharmacy label or dosing guide.
These variations do not change the actual strength of your GLP-1 medication, but simply alter the liquid volume you inject.
The purpose of additive ingredients
While your prescription’s primary focus is the active GLP-1 medication (e.g., semaglutide or tirzepatide), additives like glycine, B12, or B6 are included to provide additional supportive benefits:
Glycine
Purpose: Glycine is a naturally occurring amino acid that may be included. It can contribute to formulation characteristics such as pH balance and solubility. While glycine plays several important roles in the body, its inclusion in compounded medications reflects formulation design rather than a distinct therapeutic effect.
B12 (methylcobalamin or cyanocobalamin)
Purpose: Vitamin B12 plays a key role in energy production, nerve health, and red blood cell formation. Including B12 in your formulation may help support overall well-being and may help reduce fatigue during treatment.
B6 (pyridoxine)
Purpose: Vitamin B6 is involved in energy metabolism and neurotransmitter production, which supports overall well-being. In some formulations, B6 may also help support digestive comfort, including occasional nausea, particularly during dosage changes.
Note: These additives do not change the strength or effectiveness of the active medication
Troubleshooting common concerns
Concern: "Why did my syringe volume change?"
If your syringe's measurement (e.g., units or milliliters) changes, it’s likely due to a difference in the concentration of your medication. Even with changed syringe volumes, your prescribed dose in milligrams (e.g., 0.2 mg) remains consistent. Always follow instructions for how many units/milliliters to administer for your dose. When in doubt, visit https://portal.tryshed.com/support and message "Talk to a nurse". The clinical team is always here to support you.
Concern: "What does 'glycine starter' mean?"
If your medication is labeled as a ‘glycine starter,’ it means that glycine has been included in your prescription as part of the formulation, and that you are enrolled in the “starter” titration program.
Key takeaways
Changes in medication formulations or syringe volumes often occur due to differences in compounding practices among partnered pharmacies.
Additive ingredients like glycine, B12, or B6 provide specific benefits but do not alter the strength of your prescribed GLP-1 medication.
Always follow the dosing instructions provided with your medication to ensure proper administration.
If you have further questions about your specific formulation, your healthcare provider or pharmacist is best placed to help clarify any uncertainties.
Compounded medications are prepared by licensed pharmacies to meet individual patient needs. While they are not reviewed or approved by the FDA for safety or effectiveness, they are made in accordance with strict regulatory guidelines. Prescription is only available after consultation with a licensed provider to determine if treatment is appropriate.