Why does my medication look different between shipments?

It's normal for your medication's color, label format, or the number of syringe units to change between shipments. These changes usually come from one of three sources: a change in the added ingredient (such as B6, B12, glycine or L-carnitine), a concentration change in the vial, or your order being fulfilled by a different pharmacy partner.

If the color changed: This reflects a change in the added ingredient, not the active medication. A vial with B6 appears clear or slightly yellow, and a vial with B12 appears pink or red. Formulations with glycine or L-carnitine have no B-vitamin tint. Your vial label lists every ingredient. All formulations are safe and effective.

If the units changed: Check the concentration on your new vial label (mg/mL). Your provider will update your instructions to match. Always confirm your dose in milligrams, not just units, before injecting.

If your units or injection volume changed

A change from 100 units to 50 units (1.0 mL to 0.5 mL) can happen when the pharmacy sends a vial that is twice as concentrated. For example, 2.5 mg is 100 units from a 2.5 mg/mL vial and 50 units from a 5 mg/mL vial. The dose is the same. Only the amount of liquid changed.

The concentration depends on what the pharmacy has available, so it can change between shipments even when you did not ask for it and even when your dose has not changed. Check the mg/mL on every new vial before your first injection and compare it with your instructions. To compare, work out your dose in milligrams for the old vial and the new vial. If the milligrams match, nothing changed. If they do not match and you were not told your dose changed, message your care team before injecting.

A different vial concentration changes the number of units you draw. It does not change the milligram dose you are injecting. See "Dose vs. concentration: why your vial says a bigger number" for more examples.

If the label format or pharmacy name changed: Your order is routed based on your medication, any B-vitamin allergy you reported, and the state you live in. Most tirzepatide orders now come from a pharmacy that adds L-carnitine instead of B6, so if you used to receive the B6 version, your label and pharmacy name may look different. Your dose stays the same. A different partner may use a different label format, vial size, or concentration. For details on who makes your medication, see Where does my medication come from?

If your medication feels different after a new shipment

Your dose in milligrams is the same whichever pharmacy fills your order. A different pharmacy or a different vial concentration changes your unit count, not how much medication is in your dose.

That said, compounded medications can vary a little between shipments and pharmacy partners, including the formulation, the added vitamin or amino acid, and the pharmacy's inventory. It is also normal for the way your body responds to a GLP-1 medication to change over time, and your response can feel different after time off the medication or when you move between providers or pharmacies.

If your appetite or fullness feels noticeably different after a new shipment:

• Check the mg/mL on your new vial, and make sure the units you draw match your milligram dose (see the section above).
• Make sure your medication has been stored as directed (see "How do I store, handle, and inject my GLP-1 medication?").
• Message your care team. Your provider will review your dose, your progress, and your plan. Please do not change your dose on your own.

If you have new or worse side effects after a new shipment

Nausea, stomach upset, loose stools, bloating, and reflux are common with GLP-1 medications. They are more often related to your dose, what and how much you eat, and how much you drink than to which pharmacy filled your order. The active medication is the same.

Before assuming the new vial is the cause:

• Check that your units still match your milligram dose. If you have been drawing more than your dose calls for, that can explain new side effects (see "Dose vs. concentration: why your vial says a bigger number").
• Look at meals and fluids. It can help to keep a food journal, get enough protein, fiber, and water, and limit foods and drinks that tend to upset your stomach. For reflux, try smaller, more frequent meals and avoid lying down right after eating.

Then message your care team. Your provider can review your dose and plan, including whether your dose or schedule should be adjusted. Please do not change or split your dose on your own.

Get help promptly if you cannot keep fluids down, have repeated vomiting, or have severe or worsening stomach pain.

What the added ingredients do

Tirzepatide + B6: Some patients receive this version, depending on their state and plan. It doesn't change your dose. The solution appears clear or slightly yellow.

Semaglutide + B6: Vitamin B6 is a common added ingredient. It doesn't change your dose. The solution appears clear or slightly yellow.

Semaglutide + Glycine: Glycine is an amino acid, not a B vitamin, so it's a good option if you have a B-vitamin allergy or sensitivity. The solution is clear or near-colourless.

Tirzepatide or Semaglutide + L-Carnitine: This is what most tirzepatide patients now receive: L-carnitine is added instead of a B vitamin. L-carnitine is not a B vitamin, so it adds no B-vitamin tint. Like every added ingredient, it does not change your dose.

All formulations use the base form of the active ingredient, not a salt form, and are made by licensed compounding pharmacies. The added vitamin (or amino acid) does not change your dose.

How much B6 is in my vial, and could it be causing symptoms?

The vial label lists the amount of the added vitamin per mL. The added vitamin does not change your tirzepatide or semaglutide dose. Your dose in milligrams is the active medication only.

A formulation with a B vitamin can have a different concentration than one without, so your units can change when your formulation changes. Compare the milligrams, not the units. If your unit count went up and the concentration of the medication did not change, you are drawing more medication, and you should confirm that with your care team.

B6 is unlikely to be the cause of diarrhea, but it cannot be ruled out. If your symptoms continue and you suspect the added vitamin, tell your care team. If you have a B-vitamin allergy or sensitivity, your medication can be made with L-carnitine or glycine instead of a B vitamin. Which formulation you can receive depends on your medication, your state, and any B-vitamin allergy you reported.