Mounjaro is a prescription medicine and not everyone qualifies. The eligibility criteria exist for two reasons. First, they match the conditions where the medication has been shown to do more good than harm. Second, they identify people for whom the medication would not be safe.

For Chronic Weight Management

The SAHPRA approved indication (October 2025) is for adults with:

  • BMI of 30 kg/m² or higher (clinical obesity), or
  • BMI of 27 to 29.9 kg/m² with at least one weight related health condition, such as:
    • Type 2 diabetes
    • Pre-diabetes
    • High blood pressure (hypertension)
    • High cholesterol (dyslipidaemia)
    • Obstructive sleep apnoea
    • Cardiovascular disease
    • Polycystic ovary syndrome (PCOS) with significant metabolic features
    • Severe joint disease where weight reduction would help

Used as an adjunct to a reduced calorie diet and increased physical activity. The lifestyle component is part of the approved indication, not optional.

For Type 2 Diabetes

The SAHPRA approved indication (December 2024) is for adults with insufficiently controlled type 2 diabetes, used as an adjunct to diet and exercise. There is no BMI threshold for this indication, although in practice most people with type 2 diabetes carry excess weight.

Mounjaro can be used as monotherapy or alongside other diabetes medications.

How To Calculate Your BMI

BMI is calculated as weight in kilograms divided by height in metres squared. Example: 85 kg divided by (1.75 x 1.75) = 27.8.

BMI categories:

  • Below 18.5: underweight
  • 18.5 to 24.9: normal weight
  • 25 to 29.9: overweight
  • 30 to 34.9: class 1 obesity
  • 35 to 39.9: class 2 obesity
  • 40 and above: class 3 obesity

BMI is an imperfect measure. It does not distinguish muscle from fat, so very muscular people can have a high BMI without excess body fat. The consulting doctor will look at BMI alongside waist circumference and other markers.

Who Mounjaro Is Not Suitable For

Absolute contraindications

Mounjaro should not be used at all if you have:

  • Personal or family history of medullary thyroid carcinoma
  • Multiple endocrine neoplasia type 2 (MEN2) syndrome
  • Prior serious allergic reaction to tirzepatide or any of its ingredients

Reasons not to use

Mounjaro is also avoided or used with great caution in:

  • Type 1 diabetes (not indicated)
  • Diabetic ketoacidosis
  • Pregnancy or active plans to conceive within a month
  • Breastfeeding
  • Active pancreatitis or history of pancreatitis
  • Severe gastrointestinal disease, particularly gastroparesis
  • Active gallbladder disease
  • Severe liver disease (limited safety data)
  • Severe kidney impairment (eGFR below 30, caution and possible dose adjustment)
  • Active or recent severe eating disorder (case by case)
  • Severe diabetic retinopathy (caution, eye assessment first)
  • Under 18 years of age (not approved)

Find Out If You Qualify

An online consultation walks through eligibility including BMI, medical history, and any factors that might rule out treatment.

Start Consultation

Special Considerations

Older adults

No upper age limit, but older adults may need extra caution around kidney function, multiple medications, and risk of dehydration from gastrointestinal side effects.

BMI just under the threshold

If your BMI is just under 27, the consulting doctor cannot prescribe Mounjaro for weight management. This is not a marketing rule, it is the SAHPRA approved indication. Other interventions are usually more appropriate for people in the overweight (but not obese, without comorbidities) range.

Previous bariatric surgery

Mounjaro can be used after bariatric surgery in some cases, particularly where weight regain has occurred. This needs careful assessment because the altered gut anatomy changes how gastric emptying works.

Eating disorder history

A medication that significantly reduces appetite needs careful consideration in anyone with a history of restrictive eating. Some people can safely use it under close supervision, others cannot. The consulting doctor will assess.

What If You Are Not Eligible

If Mounjaro is not appropriate for you, several other approaches may be. These include:

  • Liraglutide (Saxenda), an older GLP-1 daily injection, suitable for some people not eligible for tirzepatide
  • Orlistat (Xenical), an oral medication that blocks fat absorption
  • Structured lifestyle support without medication
  • Bariatric surgery for severe obesity where medication has not been sufficient

The consulting doctor will discuss alternatives if Mounjaro is not suitable.

Related Reading

Frequently Asked

BMI of 30 or higher (obesity), or BMI of 27 to 29.9 with at least one weight related health condition like type 2 diabetes, high blood pressure, sleep apnoea, or high cholesterol.

No. Mounjaro is approved for people with obesity or for overweight people with weight related conditions. It is not approved or appropriate for cosmetic weight loss in people who are not clinically overweight or obese.

BMI is weight in kilograms divided by height in metres squared. For example, 80 kg divided by (1.7 x 1.7) equals BMI of around 27.7. Many online calculators do this automatically, including in the consultation form.

Mounjaro is approved for adults aged 18 and over. There is no upper age limit in the indication, though older adults may need extra consideration around kidney function and other medications.