The short version
- Nausea, constipation, diarrhoea, reflux and fatigue are the common ones, and they usually ease.
- The starter dose is deliberately too low to work. That is not a faulty pen.
- Severe abdominal pain that bores through to your back needs urgent medical attention.
- Tirzepatide can reduce the reliability of oral contraceptives for four weeks after starting and after each increase.
The first month is the part people quit during. Almost all of it is predictable, and most of it settles. Knowing the shape of it in advance makes the difference between riding it out and abandoning an expensive pen.
Week one
You take one injection and, for the first few days, the most noticeable change is that food stops being interesting. Appetite drops. Portions that were normal last week feel like too much halfway through.
Nausea, if it comes, usually appears within a day or two of the injection and fades before the next one. It is worst in the 48 hours after the dose. Many people find evening injections easier because they sleep through the peak.
Weeks two and three
Bowel habits change. Constipation is more common than diarrhoea on these medicines, and it responds to water, fibre and movement. Heartburn and burping also turn up here, because the stomach is emptying more slowly than you are used to.
Fatigue is real and under-discussed. Part of it is simply eating far less than before. If you have cut your intake in half without noticing, you will feel it by the third week.
Week four and the first step up
The starter dose exists to let your gut adapt, not to produce weight loss. When you move up, expect a smaller repeat of week one. Each escalation tends to bring a milder version of the same symptoms.
If week one was rough, say so before stepping up. Staying at a dose for longer is a normal, legitimate adjustment, and it is a decision to make with your doctor rather than on your own.
What counts as common
The manufacturers' leaflets list these as very common, meaning more than one person in ten: nausea, diarrhoea, vomiting, abdominal pain, constipation, fatigue and reduced appetite. Low blood sugar is very common when these medicines are combined with insulin or a sulphonylurea.
Listed as common, meaning up to one in ten: dizziness, low blood pressure, indigestion, bloating, reflux, hair loss, injection-site reactions, a faster heart rate, raised pancreatic enzymes, gallstones and gallbladder inflammation.
What is not routine
Get medical help urgently for: severe, persistent abdominal pain that radiates to your back, with or without vomiting, which can indicate pancreatitis; signs of gallbladder trouble such as pain under the right ribs, fever or yellowing of the eyes; vomiting so persistent that you cannot keep fluids down; or symptoms of a serious allergic reaction such as swelling of the face or throat and difficulty breathing.
Two things to sort out before your first injection
- Contraindications. These medicines are not for people with a personal or family history of medullary thyroid carcinoma or MEN 2, and previous pancreatitis needs a conversation with your doctor.
- Contraception. Tirzepatide can reduce absorption of oral contraceptives. The leaflet advises a barrier method or a non-oral method for four weeks after starting and for four weeks after each dose increase. Neither medicine is for use in pregnancy.
Practical things that help
- Eat smaller and earlier. Stop at the first sign of fullness rather than the usual one.
- Drink more than feels necessary. Reduced appetite usually means reduced fluid intake too, and dehydration in Nigerian heat makes everything worse.
- Protect protein. Eat it first in the meal, while you still have room.
- Pick an injection day you can control, so the rough 48 hours do not land on an owambe or a travel day.
- Do not double up after a missed dose. Follow the leaflet's instructions for a missed injection.
If you are eating so little that you feel faint, that is not success. Our guide to eating well on Nigerian food covers what to prioritise when appetite is gone.
Questions About Your First Month?
Message us about dosing, timing and storage. For anything clinical, speak to your doctor first.
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