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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.

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Eli Lilly MJ vs a generic Tirzepatide

22 replies

WLQuestions101 · 27/08/2026 08:18

MJ vs generic Tirzepatide- has anyone got any experience of switching from MJ to a generic Tirz?

I've done just this as the prices for MJ are no longer sustainable and i just wondered if anyone else has done the same and If so, did you notice any difference in the efficacy?

(Yes im aware that buying non branded tirz involves the grey market but no judgements please as comes from a reputable source)

OP posts:
EBearhug · 27/08/2026 08:33

If the ingredients are the same on the BNF, it should be okay.

izzy2076 · 27/08/2026 08:42

Yes. They work exactly the same. Sometimes better if they are overfilled.

Ketra · 27/08/2026 08:45

Efficacy is always going to differ if you buy on the grey market simple because you don't know what you are buying. When some of the fake Mounjaro has been tested in the past it's ranged from being different drugs (Insulin and semaglutide were the most common) or being tirzepatide but in very different concentrations - some of the pens were much weaker than sold (think 1 mg but sold as 15mg) but others were much stronger. Unfortunately there is no way of knowing what you actually have, unless you personally get your specific batch tested, so no way of knowing what the efficacy will be like.

WeAllHaveWings · 27/08/2026 08:59

Once tirzepatide is out of patent and we have properly regulated, legitimate generic sources, then yes, absolutely, it could be an option. But we’re still a few years away from that.

Until then, buying unregulated, illegal drugs based on TikTok hype and taking drug composition and dosing advice from the University of Reddit School of Advanced Armchair Pharmacology is really not a particularly sensible life choice.

There’s a reason medicines are tested, regulated and prescribed by people who actually went to medical school rather than someone called PeptideKing69 with a spreadsheet.

Stormyrose · 27/08/2026 09:04

It’s not generic though op, because that’s not something that’s available. It is illegal product, with no quality control. So you don’t know what you’re injecting.

now don’t get me wrong, mostly it’s fine, but every single death globally due to th4 drugs is due to this stuff. And it’s fine until it’s not. So it is an inherent risk that can leave you with life changing damage or death.

no one can even tell you the scale of the risk, and that’s becaude you’ve no idea where fhe product is coming from, or what it is, just what someone says. And as said, you could inject 20 times and it’s fine. And then it’s not. Or it could be a substance that is causing uou huge damage internally. Being built up with each injection, and you don’t know until you do and it’s irreversible.

GreenFootstool · 27/08/2026 09:09

There is no reputable source.

It is not a grey market.

It's illegal to sell and that's the end of it.

The drugs you're buying have no quality control that can be proven around what the drug is that you're taking, sterility or dosage.

Stormyrose · 27/08/2026 09:11

Yes it is not a grey market, this is black market.

Ratherhaveacupofteaandabiscuit · 27/08/2026 09:16

There is no “grey market”.

No “reputable source” sells unlicensed drugs.

You can’t post about buying drugs illegally and expect no judgement.

You are endangering your own life and by posting this may well encourage others to do the same.

GiveMeWordGames · 27/08/2026 09:20

Ratherhaveacupofteaandabiscuit · 27/08/2026 09:16

There is no “grey market”.

No “reputable source” sells unlicensed drugs.

You can’t post about buying drugs illegally and expect no judgement.

You are endangering your own life and by posting this may well encourage others to do the same.

Nailed it.

WeAllHaveWings · 27/08/2026 09:23

EBearhug · 27/08/2026 08:33

If the ingredients are the same on the BNF, it should be okay.

That’s not really how the BNF works. The BNF tells you about the medicine and its approved use, dose, safety and interactions. It doesn’t certify that some unregulated vial bought from the black market actually contains what the label says it does, or that it was manufactured, stored and handled properly.

“Same ingredients” on a bit of paper isn’t the same thing as a regulated medicine. There’s more to knowing a medicine is safe than recognising the name of the active ingredient someone stuck on the label.

No one should be injecting a medication that fingers crossed 🤞 “should be okay” and hopefully not cause you harm.

PhysicsBowlChampion · 27/08/2026 09:39

Can’t say anything more than others have said apart from run a million miles away from this. Have you lost your mind? You and your health matter.

WeAllHaveWings · 27/08/2026 09:40

izzy2076 · 27/08/2026 08:42

Yes. They work exactly the same. Sometimes better if they are overfilled.

“sometimes better because they’re overfilled” isn’t exactly a reassuring argument for an unregulated medicine. If the dose is supposed to be X, getting more than X because someone has decided to, or unknowingly, overfilled the vial isn’t a feature I’d be particularly keen to test on myself. 😂

It really astounds me how such clearly ridiculous advice can be shared so recklessly. Who/what has convinced you so easily this could ever be ok?

Stormyrose · 27/08/2026 09:52

It shocks me as well. Sane people, likely many of whom would not take any other illegal drugs, injecting themselves with fake product, actually buying it and injecting it into themselves go be slim.

and saying it’s a grey market and generic tirz, without even researching to see that no such thing exists,

there is no substantiation of the ingredients, the quality, the cold chain, the manufacturing conditions, either buy it from a dodgy hairdresser or beauty salon, someone on tic tok or down the gym, and hope you’re not the one who gets the dodgy product and injects yourself with an over dose of insulin or something else.

the phrase dying to be slim never rang more true,

MrsAvocet · 27/08/2026 10:27

You're talking as if you're making a choice between Panadol and a supermarket branded paracetamol OP - that's a genuine "branded vs generic" choice. But whilst a drug is still under patent there is no generic version.
No doubt that once these drugs are out of patent lots of other companies will start producing them in a safe and properly regulated manner. When that happens your question will be a sensible one.
But right now, "generic" is a euphemism for "illegal" when applied to weight loss injections. Sure, the absolute bottom line is that everyone who sells drugs is doing it to make money, but the legitimate pharmaceutical industry is regulated and operates to recognised safety standards...criminal drug dealers, not so much. There is no "reputable" source of illegal drugs. Why would you think that anyone who is breaking the law in this way cares about safety and trust them with your health?

BeckyAMumsnet · 27/08/2026 11:42

Hi all. We’ve had a number of reports recently about the amount of discussion around so-called “grey market” weight-loss injections, so thought it was worth discussing further. Talking about this, in itself, isn't against our rules. People are going to discuss what they’ve seen, and in practice these threads often contain some pretty robust warnings as you can see here. We'll step in if threads move towards advice on how to obtain these meds, etc. Please report anything you see that is along those lines.

EBearhug · 27/08/2026 12:51

WeAllHaveWings · 27/08/2026 09:23

That’s not really how the BNF works. The BNF tells you about the medicine and its approved use, dose, safety and interactions. It doesn’t certify that some unregulated vial bought from the black market actually contains what the label says it does, or that it was manufactured, stored and handled properly.

“Same ingredients” on a bit of paper isn’t the same thing as a regulated medicine. There’s more to knowing a medicine is safe than recognising the name of the active ingredient someone stuck on the label.

No one should be injecting a medication that fingers crossed 🤞 “should be okay” and hopefully not cause you harm.

But if it's black market,it won't be listed anyway.

kiwiane · 27/08/2026 13:19

I wouldn’t take the risk; instead, I would buy MJ and cut costs by trying a smaller dose / making the pen last longer.

WeAllHaveWings · 27/08/2026 14:14

EBearhug · 27/08/2026 12:51

But if it's black market,it won't be listed anyway.

I assume what they mean is that if their mystery vial has a sticky label on it, or comes with a bit of paper labelled “COA” claiming the ingredients match the BNF, then obviously we can all relax and trust the criminals selling it because everything must be perfectly legit 🤦🏻‍♀️

SethAndReubenTooSendGaloshes · 27/08/2026 14:18

EBearhug · 27/08/2026 08:33

If the ingredients are the same on the BNF, it should be okay.

How could you possibly know the ingredients of the 'generic' aka fake?

PhysicsBowlChampion · 27/08/2026 15:05

Ignore that post. Got my pharmacology wrong😂

EBearhug · 27/08/2026 17:57

SethAndReubenTooSendGaloshes · 27/08/2026 14:18

How could you possibly know the ingredients of the 'generic' aka fake?

You won't. That was y point, but clearly I wasn't clear.

MeridaBrave · 28/08/2026 04:57

There is no such thing as “generic tirzepatide”.
it’s an illegal unregulated copy. So your experience will be different to someone else’s and each batch will vary.

if you need to cut costs a possible way could be to find a friend who also takes and then buy bigger pens and stretch over 8-12 weeks. Eg find 2 friends all take 5mg and buy 15mg pen every three months. Yes - means pen will be used over 30 days but at least this way you know what you are getting (a licensed product)

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