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Weight loss injections/treatments

Discuss weight-loss injections and treatments, including personal experiences. Mumsnet hasn't checked the qualifications of anyone posting here. You may wish to speak to a medical professional before starting any treatments.

When does mounjaro start kicking in?

68 replies

HaychEss · 25/11/2025 19:10

Guys i just took my first dose of 2.5 yesterday and feel no different other than feeling a little more tired. When does it start to take effect?

OP posts:
PumpkinTwistyWindToots · 25/11/2025 21:56

Pottersciderbar82 · 25/11/2025 21:42

I’m like a Trojan fucking warrior. Nothing stops me, especially when MJ is my last and only hope to lose the weight.
Sickness and headache will not defeat me under any circumstances.
Next dose up, similar but more severe nausea without the vomiting, headache horrendous and not responsive to the usual paracetamol, lasted 2 days.

On 7.5 now with zero loss for around 11 weeks on 2.5 and 5mgs.
Zero loss week one of 7.5mgs despite doing everything right and having no appetite and eating very little.
I suppose it just doesn’t work for everyone.

When you say it doesn't work for everyone what do you mean? If you're having appetite suppression and eating in a calorie deficit as a result then it's working. If you aren't losing weight then you must not be eating in sufficient calorie deficit. Are you tracking everything?

RoundandSad · 25/11/2025 22:12

@Pottersciderbar82 i'm impressed by how strong you are

Thoseslippers · 25/11/2025 22:16

Different for everyone.
Many people do not feel anything at all on 2.5ml.
Unfortunately it worked so intensely for me from the second day that I couldn't eat AT ALL and had to come off it after 6 weeks as I could barely even drink water.
I lost 2stone in that 6 weeks though. Which I guess means it worked! But it was utterly horrific and I've still got ongoing health consequences now

So really it's probably for the best the 2.5 hasn't affected you. Means you aren't very sensitive to it. Just let your body get used to it for a month then go up a dose. Keep doing that until you find the dose that works for you then stay there.

mumof5five · 25/11/2025 22:23

gallivantsaregood · 25/11/2025 20:48

I would warn against using immodium unless you actually need it or you may end up seriously constipated, which is also a very common side effect. If you do experience constipation please address it straight away. Do not wait until you've not been for a week!

Thankyou for this advice. My tummy was already a bit bad so I took it on the advice of the pharmacist. What do you recommend I use for constipation if that happens?

TryingAgainAgainAgain · 25/11/2025 22:33

But you can't know it won't work again for you until you've gone up through to the maximum dose, @Pottersciderbar82?

MrsM2025 · 25/11/2025 23:03

For me - I started it just before a bedtime and the next day the suppression was instant
I have lost nearly 4 stone in4 months but to be fair my diet was atrocious before
I have been avoiding fats / sugar
I am now on 5 mg and it is only in the last couple of weeks that I have felt it slightly not working as well as before

HappyWineDay · 26/11/2025 00:15

@Thoseslippers did you consider moving down to 1.25mg at all, if you were finding 2.5mg too much?

monjmaintainer · 26/11/2025 06:23

@HaychEssas you’ve already been well advised it varies wildly - what is helpful is to use a GLP1 plotter tool that shows a graph. Essentially even though you are staying on 2.5mg for the first month, every time you jab you get a new higher peak as it builds up in your system. If by the end of first pen you still don’t feel any difference then move up as advised to 5mg and continue. It’s rare that it doesn’t work at all but you can also start making changes to diet alongside and might just notice it gradually being easier not to snack. It’s not dramatic for everyone. I felt it within 24h, wondered if it was placebo but quickly realised not as just kept forgetting about food and having to be mindful to fuel myself, I never went above 5mg. But my friend needed to go right up to 15mg to achieve success. Everyone responds very differently.

@mumof5fiveyour Imodium to ‘stave off a bad tummy’ when you just started MJ comment scared me as taking meds that also affect the digestive system preventatively is not recommended - you can’t know which way you are going to go as a side effect and more people do seem to get constipation. Good to see the update that you consulted a pharmacist and did already have diarrhoea but also to clarify on this thread that new users should not to be taking immodium or laxatives alongside ‘just in case’ without checking with your pharmacist or provider as the impact on your guts can be significant and unpredictable.

VioletandMauve · 26/11/2025 06:34

mumof5five · 25/11/2025 22:23

Thankyou for this advice. My tummy was already a bit bad so I took it on the advice of the pharmacist. What do you recommend I use for constipation if that happens?

Psyllium husk tablets are amazing. Available on Amazon.

morningtrain · 26/11/2025 06:51

Pottersciderbar82 · 25/11/2025 19:45

Within hours of taking it I was throwing my guts up and had the worst headache ever.

That lasted around 48 hours then… oh my word!

There was silence in my head and I wasn’t interested in eating at all, when I did, I felt uncomfortably full and nauseous on very very little.
Dropped a stone in that month.

I’ve gone up and thpugh the doses and it has stopped working unfortunately for me.
But yeah, within hours for me (when it worked)

Can I ask your circumstances? I wonder why you had such severe reaction..? I’m waiting to start but am so scared of this happening.. I can’t afford to be ill! - did you take it after a meal/ what time of day? Did it happen again the second week on jab day? Do you have lots of weight to lose? Hope you don’t mind me asking? I wonder who gets most severe side effects & who doesn’t!

Prelim · 26/11/2025 07:17

Not until the maximum dose for me and even then I wouldn’t say it’s much suppression. If left to my own devices I can easily eat a lot of crisps and chocolate! My craving for ‘crap’ food have increased (I would have never touched a burger and chips before). I am slowly losing weight though. I don’t know how!!

gallivantsaregood · 26/11/2025 07:44

@mumof5five I use this. You take it every day. I was probe to being constipated a little when I started. This is gentle, doesn't cause pain and designed to be taken daily. Since taking it zero issues for me. But you do need to make sure you're drinking enough too. If I don't get enough fibre, I supplement with a few fibre gummies.

A Dose For Blocked Bellies https://share.google/Wbr0weqBTthmwQ1JF

Pottersciderbar82 · 26/11/2025 08:22

morningtrain · 26/11/2025 06:51

Can I ask your circumstances? I wonder why you had such severe reaction..? I’m waiting to start but am so scared of this happening.. I can’t afford to be ill! - did you take it after a meal/ what time of day? Did it happen again the second week on jab day? Do you have lots of weight to lose? Hope you don’t mind me asking? I wonder who gets most severe side effects & who doesn’t!

Hello.
I take it on a Friday night so that I’m not ill for work. I don’t eat anything for around 4 hours before injecting as I can’t bear vomiting.
The following week, I had the headache and milder nausea, week 3&4 nothing.
Increased dose, same again.
These side effects last around 48 hours.

Many many people have no side effects at all.

Ive around 3 stone to loose. Not shifting anything at all though unfortunately.

morningtrain · 26/11/2025 08:43

@Pottersciderbar82 I was planning on doing it Friday night too.. & have similar amount to lose. I’m not sure I’ll stick with it if it makes me feel too bad though.. especially if results aren’t immediately forthcoming!! Good luck, hope it starts to shift for you soon. Assuming it’s not that bad for you to stop so that’s good!

PigeonsandSquirrels · 26/11/2025 09:15

I take it at night and then it has taken effect by morning. I’m on 7.5 now and honestly could forget about food for days if it wasn’t for my husband always coming and asking about lunch or dinner… thankfully he does as it’s important to still eat.

mumof5five · 01/12/2025 07:36

OP if my calculations are right you are taking your second dose today? I just had my 2nd dose. How are you feeling ?

HaychEss · 02/12/2025 02:54

mumof5five · 01/12/2025 07:36

OP if my calculations are right you are taking your second dose today? I just had my 2nd dose. How are you feeling ?

Yeh had my second dose Monday evening. Feeling fine so far, although my pen got jammed which was a struggle! No weight lost yet sadly how about you?

OP posts:
alecks · 02/12/2025 05:22

HaychEss · 02/12/2025 02:54

Yeh had my second dose Monday evening. Feeling fine so far, although my pen got jammed which was a struggle! No weight lost yet sadly how about you?

It’s usually just needing a new needle when that happens OP

monjmaintainer · 02/12/2025 05:30

when I first used the pen I found the plunger really hard to do with one hand, did not expect it to be so stiff. Find a comfy position so you can use 2 hands for the injection. It does kinda stop and start pressure wise as it turns if it’s a stiff pen. Some people hate it so much they use insulin syringes to extract every dose but I did get used to it and clicks with pen needles are simpler.

BoxingHares22 · 02/12/2025 06:17

All these accounts of viniting and severe headaches really worry me. Also what happens about nutrition if people are eating so little? How do you know that your body is getting the right vitamins and minerals?

gallivantsaregood · 02/12/2025 06:48

BoxingHares22 · 02/12/2025 06:17

All these accounts of viniting and severe headaches really worry me. Also what happens about nutrition if people are eating so little? How do you know that your body is getting the right vitamins and minerals?

That's definitely not been my experience. If your appetite is so suppressed you can't eat, or you're vomiting then I'd say the dose is too high.

morningtrain · 02/12/2025 09:19

@BoxingHares22im on day 4 & was so scared of side effects. I did have a horrendous headache for 24 hrs yesterday but I suffer with headaches regularly anyway & have had them when going LC before too.. so think it’s the change in eating pattern rather than the jab itself that caused that. Feeling great again today.. no nausea, vomiting whatsoever. I’m eating a really healthy diet - much more so than before because I don’t feel I want to consume rubbish - I don’t know how it affects your brain in this way but it’s always been what crippled me on WL journeys before.. I generally prefer crap food so a week of healthy eating was boring to me: I use food as reward & with this medication that part of my psychology has literally been switched off. I’ve just finished a bowl of Greek yogurt, berries, seeds & am planning a hummus salad wrap for lunch, just no crap in between! I’d thoroughly recommend it.

Howinthehelldidthishappen · 02/12/2025 10:14

For me it was immediate, with a funny taste in the back of my mouth, and the strangest sensation of being full within about 20 minutes.

alecks · 02/12/2025 10:20

BoxingHares22 · 02/12/2025 06:17

All these accounts of viniting and severe headaches really worry me. Also what happens about nutrition if people are eating so little? How do you know that your body is getting the right vitamins and minerals?

People who are barely eating are crazy. Yes they get the results but they are probably doing more damage than when they were obese tbh. I really struggled to eat in the early weeks but I made sure I did have the right amount of food. I never moved up because suppressing my appetite to the point I am barely able to eat isn’t the goal for me. 2.5mg has served me well.

PearlTeapot · 02/12/2025 18:19

Agree. If you're vomiting, stop! Yes you'll lose weight but at what cost?!