5 common mistakes when starting a GLP-1 protocol

The biggest predictor of whether someone sticks with a GLP-1 past month two isn’t the compound, the dose, or even the brand. It’s whether they made one of these five mistakes in week one.

1. Starting at the wrong dose

The most common error. Someone reads “2.4 mg semaglutide for weight loss” and starts there. The protocol is 0.25 mg → 0.5 → 1.0 → 1.7 → 2.4, stepped every four weeks. Skipping the ramp turns “manageable mild nausea” into “vomiting for three days straight.”

Tirzepatide is even less forgiving — start at 2.5 mg, step to 5, 7.5, 10, 12.5, 15. Each step is a 4-week minimum.

2. Eating like you don’t have a GLP-1 on board

GLP-1s slow gastric emptying. A heavy meal that used to clear in 90 minutes now sits for 4-5 hours. Late-evening pizza + early-morning workout = nausea on the treadmill.

Switch to lighter, more frequent meals. Higher protein, lower fat (fat slows emptying further). Stop eating 3 hours before bed.

3. Ignoring hydration

Reduced appetite plus reduced thirst signaling plus the occasional vomiting episode = dehydration within a week. Headaches, fatigue, dizziness on standing. Most people blame the medication and quit.

Set a 2.5 L/day water target. Electrolyte mix once a day if you’re sweating.

4. Not warning your doctor about other meds

Insulin or sulfonylureas + GLP-1 = hypoglycemia risk. Oral contraceptives may absorb differently with slowed emptying. Levothyroxine, antibiotics, anything time-sensitive — talk to your prescriber.

If you’re on a sleep med and the GLP-1 makes you fatigued, that’s an interaction worth discussing too.

5. Forgetting the weekly cadence

Semaglutide and tirzepatide are weekly. Cagrilintide is weekly. CagriSema is weekly. The half-lives are 5-7 days specifically so you don’t need daily injections — but it also means missing one shot leaves you in withdrawal within 48 hours.

Pick a day. Same day every week. Set the Peptora reminder. Inject before breakfast or any meal you can stomach if you’re queasy.

What the dose calculator does

Open Peptora → Reiknivél → pick your peptide → enter your vial size and BAC water volume → it tells you exactly how many insulin syringe units to draw for whichever titration step you’re on. The interaction warnings flag the common mistakes automatically (never stack two GLP-1s, never combine cagri already-in-CagriSema with extra cagri, etc).

If you’ve already made one of these mistakes — don’t quit, just back off the dose. Most side effects resolve in 5-7 days at the lower step. The compounds work, but only on the protocol they were trialed at.

Not medical advice. Always work with a qualified prescriber.