You were handed a pen and a leaflet in tiny print.

1. How many clicks is my dose?

   Lots of women count clicks to take part of a dose from a stronger pen. The figure passed around online is about 60 clicks for a full dose. Eli Lilly doesn't publish a click count, so treat it as rough. The classic mistake is turning to the stop out of habit on a stronger pen, which gives you the full strength in one go.

   Ask your prescriber: "What's my dose in clicks on this pen?"

   Chapter 2 of the guide has the click maths for every pen.

2. Does the fridge make my pen last longer?

   No: once opened, the limit is 30 days or 4 doses, whichever comes first, fridge or not. But that's not how many women use it. A common way to save money is to buy a higher-strength pen and take part-doses, so one pen lasts two months or more. Some prescribers set it up this way. The trade: 30 days is as long as an opened pen was tested. Past that, no one has measured how strong or sterile it still is. The real risks are a weaker dose near the end and an infected injection site.

   Ask your prescriber: "My pen will run past 30 days. Are you happy with that?"

   Chapter 2 of the guide sets out the whole trade.

3. 2.5mg has stopped working. Have I stalled?

   That's normal: 2.5mg is a starter dose, and its effect often fades. It's there to let your gut adjust, and the big trial results came from 5mg, 10mg and 15mg, not 2.5mg. The fade is usually when your prescriber steps you up to 5mg, though staying a bit longer is fine if the side effects were rough. Stalls later on are normal too: check protein, weekend drinks and your waist measurement before blaming the dose.

   Chapter 3 of the guide goes further.

4. Why does every step up cost more?

   Not every step does: per pen, 2.5mg is £133, 5mg £180, 7.5mg and 10mg £255, and 12.5mg and 15mg £330. Those are UK reference prices from September 2025, when Eli Lilly raised them sharply, and private prices vary. The jump that stings is 5mg to 7.5mg, up £75 a pen. Climbing slowly is allowed, and cheapest: in the main trial, 15mg added only about 1.5 percentage points of weight loss over 10mg.

   Chapter 7 of the guide does the full sums.

5. I'm worried about losing muscle at my age.

   Some goes with any big weight loss: in the main trial's body scans, about a quarter of the weight lost was lean tissue, mostly muscle and water. That's not the drug eating your muscle, but at 50, age and menopause are already taking some, so protect it. A common starting point is 1.2g of protein per kg of body weight a day (about 95g at 80kg), plus strength exercise twice a week. Ask your GP first if you have kidney problems.

   Chapter 5 of the guide opens with it.

6. My hair is falling out. Will it grow back?

   Usually, yes: shedding from fast weight loss tends to grow back over the following months. It's a listed common side effect: about 1 in 20 people on tirzepatide in the main trial, against 1 in 100 on a dummy injection. The menopause can thin hair too, so keep your protein up, and ask your GP to check iron, B12 and thyroid if it's falling fast.

   Chapter 4 of the guide goes further.

7. Does the jab mess with my HRT?

   The part to check is progesterone you swallow, like Utrogestan: the jab slows your stomach, so less may be absorbed. That progesterone protects your womb lining, and a combined patch or a hormonal coil like Mirena needs no change. If you swallow yours, the British Menopause Society's options are a hormonal coil, the capsule used vaginally, or a higher dose for 4 weeks after starting and each step up. Your GP or menopause clinic can set that up.

   Chapter 6 of the guide goes further.

8. I've started bleeding again. Is it the jab?

   Sometimes, but never assume it: any bleed after 12 months with no period needs your GP, promptly, every time. It's usually nothing serious, but it's always checked. Flooding or clots at any stage mean your GP this week, and spotting on HRT goes to your HRT prescriber, especially after starting or a step up. Weight loss can restart ovulation, and the jab may affect oral progesterone, so both can bring bleeds back.

   Chapter 6 of the guide has the full bleed decoder.

9. Will the weight come back when I stop?

   For most people, a good part of it does, because the old hunger signals come back. In the main trial on stopping, people switched to a dummy injection regained about 14% of their body weight over a year. Even so, they stayed about 10% lighter than when they started. Food noise usually returns first, within weeks, and the habits you build while it's quiet (protein, strength work, weekly weigh-ins) decide how much you keep.

   Chapter 10 of the guide is the plan for stopping well.

10. I'm BMI 27 and peri. Can I even get it?

    Only with a weight-related condition: Mounjaro is approved in the UK for a BMI of 30 or more, or 27 to under 30 with a condition such as high blood pressure. Others include high cholesterol, prediabetes, type 2 diabetes, sleep apnoea and heart disease; being peri isn't one. Some people fudge the questionnaire or weigh-in. The checks screen for things like pancreatitis and eating disorders, so that risk lands on you. If you don't qualify, HRT, strength work and sleep are the next things to raise with your GP.

    Chapter 8 of the guide goes further.

Sources: the UK patient leaflet and prescribing information, the NHS pages on tirzepatide and bleeding after menopause, British Menopause Society advice (April 2025), Eli Lilly's medical information, the SURMOUNT-1 and SURMOUNT-4 trials, and UK reference prices from September 2025. The guide lists every source.