Why retatrutide isn’t on the NHS yet
Retatrutide is an investigational medication made by Eli Lilly. It’s a triple-action medication that mimics the effects of three hormones: GLP-1, GIP, and glucagon.
Phase 3 trials are still running, and Eli Lilly is expected to submit retatrutide for regulatory approval once the remaining trials report results across 2026.
For a medication to reach NHS patients, it needs to clear three stages:
- MHRA marketing authorisation. The Medicines and Healthcare products Regulatory Agency assesses whether the medication is safe and effective enough to be licensed for UK use. MHRA review typically takes around seven to eight months from a valid submission.
- NICE technology appraisal. The National Institute for Health and Care Excellence assesses whether the NHS should fund the medication, by comparing the cost against the health benefits. This typically takes 6 to 18 months.
- ICB commissioning. Integrated Care Boards (ICBs) then commission the services that deliver the medication locally, which can vary by region.
Retatrutide hasn’t yet entered stage 1. For background on what retatrutide is and how the trials have gone so far, see our guide to what retatrutide is and how it compares to Mounjaro and Wegovy.
The realistic UK timeline
Wegovy and Mounjaro give a useful indication of how long the regulatory process typically takes.
| Medication |
MHRA approval |
NICE appraisal |
NHS availability |
| Wegovy (semaglutide) |
September 2021 |
TA875, March 20231 |
From 2023 via tier 3 specialist services |
| Mounjaro (tirzepatide) |
November 2023 |
TA1026, December 20242 |
Phased rollout from June 2025 |
| Retatrutide |
Expected late 2027 to mid-2028 |
Expected 2028 to 2029 |
From 2029 at the earliest |
If retatrutide follows the same pattern, we would expect an Eli Lilly regulatory filing in late 2026, MHRA approval in late 2027 to mid-2028, and NHS access through NICE from 2029 at the earliest.
The devolved nations assess medications separately. The Scottish Medicines Consortium (SMC) reviews medicines for NHS Scotland, the All Wales Medicines Strategy Group (AWMSG) for NHS Wales, and the Department of Health for Northern Ireland. Timing and access can vary across the four UK nations.
What NHS access is likely to look like
If retatrutide is approved by NICE for NHS use, eligibility is likely to follow the pattern set by Mounjaro.
The Mounjaro rollout gives the clearest picture of what to expect.
NHS England rolled out tirzepatide for weight management in cohorts after NICE TA1026 in December 2024:3
- Cohort 1 (from June 2025): adults with a body mass index (BMI) of 40 or higher and at least four of five weight-related conditions (type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease).
- Cohort 2 (from June 2026): adults with a BMI of 35 or higher and broader cohort criteria.
- Cohort 3 (from March 2027): further expansion of eligibility, with the full criteria gradually widening over the following years.
NHS England has said the full Mounjaro rollout is expected to take up to 12 years.
NICE estimated that 3.4 million people in England are eligible under the full criteria, but only around 220,000 will access it on the NHS in the first three years.3
The BMI threshold is 2.5 lower for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean backgrounds, who are at higher risk of weight-related conditions at a lower BMI.
If retatrutide is added to this pathway, it’s likely to start with the highest-need cohort and expand gradually.
Anyone whose BMI sits below the threshold, or who doesn’t have the qualifying conditions, would be unlikely to receive retatrutide on the NHS in the early years of any rollout, even after approval.
NHS access also varies by region. Each ICB decides how to deliver the medication locally, and not every GP practice participates.
Some areas use specialist weight-management services, others a primary care model with referral.
What to do in the meantime
There are three realistic options if you’re considering weight-loss medication and don’t want to wait for retatrutide.
1. Use an MHRA-approved alternative now
Mounjaro and Wegovy are both licensed for UK use and both produce significant weight loss.
Mounjaro produces an average of around 22.5% weight loss over 72 weeks at the 15 mg dose in the SURMOUNT-1 trial.4
Wegovy 7.2 mg, the higher-dose semaglutide approved by the MHRA in January 2026, produces around 18.7% over 72 weeks.
Both are available privately, with NHS access through tier 3 specialist services or the phased Mounjaro primary care rollout for those who meet eligibility criteria.
For most people not in the cohort 1 group, private prescription is the faster route.
Private monthly costs for Mounjaro range from around £159 to £359 depending on dose and provider.
2. Wait for private UK availability of retatrutide
Private prescriptions for both Wegovy and Mounjaro became available within weeks of MHRA approval, well before NHS access. Retatrutide is expected to follow the same pattern.
If MHRA approval arrives in late 2027 to mid-2028, private availability could begin from late 2027 or 2028, with NHS access from 2029.
Initial private pricing is expected to be similar to or higher than the current Mounjaro rates given the more complex triple-action.
3. Consider a clinical trial
Several TRIUMPH phase 3 trials have included UK sites.
Most are now closed to new recruitment, but other retatrutide trials (including longer-term cardiovascular and kidney outcomes studies) may still be open to UK participants.
You can check current trial recruitment status at ClinicalTrials.gov or via the Lilly Trial Guide.
Eligibility is selective, with strict BMI, age, comorbidity, and previous-treatment criteria, and some participants receive placebo. Speak with your GP before applying.
What to avoid
A fourth option, buying retatrutide from online vendors selling ‘research peptides’ or counterfeit pens, isn’t safe.
The MHRA has dismantled UK-based illicit manufacturing operations producing fake retatrutide and tirzepatide pens, and counterfeit products have been found to contain the wrong dose, the wrong drug, or contaminants.
We’ve covered this in detail in our guide to whether you can buy retatrutide online safely in the UK.
Comparing private and NHS access
The trade-off between NHS and private weight-loss medication is mostly between cost and waiting time.
NHS access is largely free at the point of care, with patients paying the standard prescription charge unless exempt. Private programmes charge for the medication, consultation, and any wraparound support.
| Route |
What’s available |
Eligibility |
Cost to patient |
| NHS (Mounjaro, primary care) |
Mounjaro, phased rollout |
BMI 40+ with 4 of 5 conditions in cohort 1; broader from June 2026 |
Standard prescription charge or free if exempt |
| NHS (tier 3 specialist services) |
Mounjaro, Wegovy |
BMI 35+ (or 32.5+ for some ethnic backgrounds) with at least one weight-related condition; referral by GP |
Standard prescription charge or free if exempt |
| Private programmes |
Mounjaro, Wegovy |
Typically BMI 30+ (or 27+ with comorbidity); varies by provider |
£159 to £359 per month for Mounjaro depending on dose and programme |
| Retatrutide (when available) |
Private first, then NHS |
Likely to mirror Mounjaro NHS criteria; private criteria typically broader |
Likely at or above current Mounjaro rates initially |
Frequently asked questions
Will retatrutide be on the NHS?
Retatrutide is likely to become available on the NHS at some point, but only after MHRA approval and a NICE technology appraisal.
The earliest realistic date is 2029, and only if NICE finds it cost-effective.
Initial NHS access is likely to be limited to people with the highest clinical need.
When can I get retatrutide privately in the UK?
Not yet. Retatrutide isn’t approved by the MHRA, so no UK doctor can legally prescribe it privately.
If MHRA approval arrives in late 2027 to mid-2028, private availability could follow within weeks, as it did with Mounjaro and Wegovy.
Will retatrutide replace Mounjaro on the NHS?
This depends on how NICE assesses retatrutide’s cost-effectiveness against Mounjaro.
If retatrutide produces better weight loss but costs significantly more, NICE may restrict it to specific patient groups while Mounjaro remains the first-line option.
The phased Mounjaro rollout is expected to continue regardless.
Can my GP prescribe retatrutide?
No. GPs can only prescribe medications licensed by the MHRA.
Retatrutide doesn’t have a UK licence, so no UK clinician (GP, specialist, or private prescriber) can lawfully prescribe it.
How much will retatrutide cost in the UK?
No official price has been set. Analysts expect private monthly costs to begin at or above current Mounjaro rates, given the more complex triple-agonist mechanism.
NHS pricing will be negotiated separately between Eli Lilly and NHS England.
Who will be eligible for retatrutide on the NHS?
NHS criteria haven’t been set because retatrutide isn’t approved.
If retatrutide follows the Mounjaro pattern, eligibility is likely to start with adults living with severe obesity (BMI 40+) and several weight-related conditions, then broaden in later cohorts.
Can I buy retatrutide online while I wait?
You can find vendors online selling ‘retatrutide’ as a research peptide or counterfeit pen, but this isn’t safe.
The MHRA has dismantled UK manufacturing operations producing fake retatrutide pens, and counterfeit products have been found to contain incorrect substances, including insulin.
See our guide on whether you can buy retatrutide online safely.
Should I switch from Mounjaro to retatrutide when it’s available?
Whether to switch is a clinical decision for you and your prescriber.
Switching from one GLP-1 medication to another isn’t always recommended, particularly if you’re losing weight steadily on your current treatment.
Retatrutide produces greater average weight loss in trials, but cross-trial comparisons should be read with care.
Is retatrutide approved anywhere in the world?
No. Retatrutide isn’t approved by any regulator, including the FDA in the U.S., the EMA in Europe, or the MHRA in the UK. Eli Lilly is expected to file with the FDA first in late 2026, with other regulators following.
Take home message
You can’t get retatrutide on the NHS in the UK in 2026. The medication isn’t approved by the MHRA, so it can’t legally be prescribed on the NHS or privately.
The most realistic UK timeline is MHRA approval in late 2027 to mid-2028, followed by NHS availability from 2029 at the earliest.
NHS access is likely to start with the highest-need cohort and expand gradually, in the same phased pattern as Mounjaro.
If you’re considering weight-loss medication now, the regulated alternatives are Mounjaro and Wegovy.
Both are available through NHS specialist services for people who meet eligibility criteria, and through private programmes for adults with a BMI of 30 or higher (or 27 with comorbidity).
Avoid online vendors selling retatrutide as a ‘research peptide’ or counterfeit pen.
These products aren’t regulated, and the MHRA has dismantled UK manufacturing operations producing fakes.
Second Nature's Mounjaro and Wegovy programmes
Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.
Why choose Second Nature over other medication providers, assuming you're eligible?
Because peace of mind matters.
We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
References
- National Institute for Health and Care Excellence. (2023). TA875: Semaglutide for managing overweight and obesity.
- National Institute for Health and Care Excellence. (2024). TA1026: Tirzepatide for managing overweight and obesity.
- NHS England. (2025). Interim commissioning guidance: implementation of NICE TA1026 (tirzepatide for weight management).
- Jastreboff, A. M., Aronne, L. J., Ahmad, N. N., et al. (2022). Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). New England Journal of Medicine, 387(3), 205-216.
- Richards, R., Whitman, M., Wren, G., & Campion, P. (2025). A remotely delivered GLP-1RA-supported specialist weight management program in adults living with obesity: retrospective service evaluation. JMIR Formative Research, 9, e72577.
