Ozempic, Mounjaro, Wegovy are now the common injectable medications being prescribed ‘off label’ for weight loss in Australia. They are a class of drug termed GLP-1 agonists which work by mimicking the action of the body’s own GLP-1 hormone to help regulate blood sugar levels and manage appetite by providing a feeling of ‘fullness’ or satiety.
Both Ozempic and Wegovy are proprietary names for the drug Semaglutide and are used in the treatment of Type 2 diabetes (NIDD) and obesity.
Mounjaro is the brand name of a newer class of GLP-1+ (1) agonist: Tirzapetide. According to studies, Mounjaro’ s benefit over Semaglutide (ie: Ozempic, Wegovy) is it maximises insulin sensitivity to potentially assist with greater weight loss in obese individuals.
Note: ALL GLP-1 agonists are contra-indicated for Type 1 (insulin-dependent) diabetics, patients with acute or chronic pancreatitis, pregnant or breast-feeding mothers.
Known side effects of GLP-1 injections:
- Nausea and/or lethargy.
• Disturbance of mood as anxiety or body dysmorphism as physical appearance dramatically alters. Some GLP-1 users report they have withdrawn socially because they have no desire to eat.
• Metabolic hormonal changes involving blood glucose and insulin levels.
• Potential nutrient deficiency due to the drug’s inhibition of hunger and continued feelings of satiety. Daily caloric intake diminishes which – over time – may lead to nutrient deficiencies.
• Dramatic, rapid weight loss can adversely affect skin structure – particularly in middle-aged (or older) people. Elastin and Collagen is reduced in this form of weight loss and not readily replaced in this age group and often results in a premature aged appearance – particularly at the neck (2).
• Significant, rapid weight loss may also cause a corresponding rise in Cortisol as the body senses a dramatic disturbance in metabolic homeostasis. Cortisol is a steroid hormone which aids the body’s response to stress, regulate inflammation, control blood pressure, and manage blood sugar levels.
Elevated Cortisol deactivates hair follicle stem cells to inhibit growth. This causes the hair follicles to enter the telogen (falling) phase of the hair growth cycle where the hair shaft is eventually shed but not replaced.
• Any long-term adverse effects from GLP-1 injections continue to be evaluated.
Scalp hair loss side effect:
The manufacturers of these GLP-1 agonists state ‘hair loss’ is NOT a commonly seen side effect of their use, rather the hair loss is due to the weight loss effect they induce. This may be so, but some patients report a telogen effluvium (TE) hair shed when commencing the drug at lowest recommended dosage and before any weight loss was observed.
Another explanation might be that the TE hair loss is being caused by hormonal changes from the effects of these GLP-1 agonist drugs.
Telogen effluvium is the diagnostic term to describe the rapid and excessive shedding of follicle scalp hair following illness, febrile fevers, sudden, dramatic weight loss or significant changes in diet, commencing or ceasing certain medications, post-natal hormonal changes, sudden emotional shock or prolonged mental stress, severe allergic reactions.
TE is arguably the most distressing way to lose one’s hair as up to 60% of scalp hair follicles simultaneously pass in to a premature termination of the ‘anagen’ (3) phase, followed by the ‘telogen’ (4) shedding phase usually one – three months after.
Ordinarily TE is considered a ‘temporary & self-correcting’ form of generalised scalp hair loss but will only fully resolve when nutrient-metabolic support is optimised to support a follicle phasing re-set.
An experienced, qualified Trichologist should be able to provide the correct diagnosis and assist with appropriate treatment if required.
Current updates (as at 12/2025):
• The WHO guidelines regarding injected GLP-1 medication such as Ozempic, Mounjaro and Wegovy are safe for the long-term treatment of obesity.
• The Australian TGA issued an advisory warning that the use of GLP-1 drugs may cause thoughts of suicide (5) or self-harm in some predisposed patients – particularly those who have become overweight from the taking of drugs prescribed for certain mental health conditions.
Consumer/Client questions:
1. Are these injections enough to help me lose weight and keep it off or do I need to do more? Ms. PB – South Coast NSW.
Reply: to permanently reduce your overall body weight you need a combined approach of diet, exercise and assessment of the relevant pathology which influences weight and metabolic activity. I can offer you a consultation – face to face or via tele-conference – to help guide you in these areas.
2. My hair was thinning before commencing my Mounjaro injections but is now falling out noticeably. Do you think it’s the injection/s causing this or some other condition … really appreciate your advice? Mrs. LS – Sydney.
Reply: as a woman the state of your state of your hair is generally reflecting inner disturbance: nutritional, metabolic, autoimmune issues, or where you may be hormonally at your particular stage of life. Being significantly over your BMI (unfortunately) gives rise to complex metabolic and hormonal disorders such as Insulin Resistance – a pre-diabetic state – which in turn bi-directionally drives oestrogen dominance (and vice versa). I can offer you a professional consultation to assess these potential concerns for you and help guide you in correcting them.
3. I have suffered distressingly excessive hair loss since I commenced my weight loss injections in early 2025. Will I go completely bald if I continue weight loss injections or will my hair loss eventually settle and grow back? Please help as I am desperate to both lose the weight AND keep my hair ☹ Mrs. RM – North Coast, NSW.
Reply: the changes which occur within your body when you commence these weight loss treatments are complex and multi-factorial – all of which may activate a Telogen effluvium (TE) type scalp hair shedding. Although TE is the most distressing form of hair loss one might experience, it also potentially has the best prognosis for complete recovery – so it’s extremely unlikely you’ll become bald or your hair won’t recover. My article (above) should offer you some insights into this particular for of hair loss; should you require further guidance with your concerns I can offer you a consultation – face to face or via tele-conference – to assist you if further investigations are required.
1. Mounjaro is both a GLP-1 and GIP receptor agonist; GIP means glucose-dependent insulinotropic polypeptide – another post-prandial (ie: after eating) hormone our body’s produces to promote satiety.
2. Ie: a crepey, ‘turkey neck’ appearance now referred to ‘Ozempic neck’ in GLP-1 users.
3. Anagen: growth phase of a hair follicle.
4. Catagen/Telogen: the combined resting and hair shaft shedding of the hair follicle.
5. Suicidal ideation.
Copyright – Anthony Pearce May 2025 (revised January 2026).