GLP‑1 Weight Loss Jabs: The Risks We’re Not Talking About Enough
Following yesterday’s article, it was important to build on it since the weight loss jabs made it to the top of the news again today.
The Time online has written a very damning article, somewhat echoing what I (and every practitioner worldwide) see in clinics.
Let’s dive in…
GLP‑1 Weight Loss Injections: Benefits, Hidden Risks, and How to Protect Your Health
GLP‑1 weight loss injections such as semaglutide and tirzepatide have been called game‑changers for obesity and metabolic health. They are all over the headlines, social media feeds, and celebrity interviews. Recent reports, including Robbie Williams speaking publicly about developing scurvy and visual problems while using Mounjaro, have reignited debate about how safe these drugs really are in real‑world use. Scurvy, a vitamin C deficiency disease associated with sailors in the 17th and 18th centuries, is not something most people expect to hear about in 2025. Yet in the context of powerful appetite suppression and extreme dietary restriction, severe micronutrient deficiencies are biologically plausible.
Many chronic diseases are resurfacing in what would be “healthy” or slightly overweight individuals, including sarcopenia (loss of skeletal muscle mass and strength, often associated with old age), osteopenia (loss of bone mass), and osteoporosis, with an increased risk of fractures.
The reality is complex. On one hand, there is solid clinical evidence that GLP‑1 receptor agonists can produce substantial weight loss and improve blood sugar control and cardiovascular risk factors in people with obesity or type 2 diabetes. On the other, there is growing concern about rapid weight loss, muscle loss, micronutrient deficiencies, bone health, mental health, and the lack of structured support for many people who are using these medications mainly as weight‑loss tools rather than as part of a comprehensive medical plan. This article aims to take a calm, evidence‑led look at both sides and outline what you can do to protect your health if you are considering or already using GLP‑1 weight loss injections.
What Are GLP‑1 Weight Loss Injections and How Do They Work?
GLP‑1 receptor agonists such as semaglutide and tirzepatide are medications that mimic or enhance the effects of glucagon‑like peptide‑1, a hormone naturally released from the gut after eating. GLP‑1 acts on the brain to reduce appetite and increase satiety, slows gastric emptying so food leaves the stomach more slowly, and stimulates insulin secretion while suppressing glucagon when glucose levels are high. In people with type 2 diabetes, these actions can help lower blood glucose and improve HbA1c. In people with overweight or obesity, the appetite‑reducing effect translates into lower food intake and rapid weight loss.
Large randomised controlled trials in adults with obesity have shown that weekly injections of semaglutide and tirzepatide, combined with lifestyle advice, can produce average weight loss in the range of around 10–20% of starting body weight over 1–2 years, with associated improvements in blood pressure, blood lipids, glycaemic control, and some cardiovascular outcomes. These are clinically meaningful results, particularly for people at high risk of type 2 diabetes, heart disease, or fatty liver disease. This is why GLP‑1 receptor agonists are being widely adopted in diabetes and obesity medicine.
However, the picture is more nuanced when these drugs are used off‑label or without adequate medical and nutritional supervision, especially in people whose primary goal is aesthetic weight loss rather than management of a serious metabolic condition.
Rapid Weight Loss, Lean Mass Loss, and Muscle Health
One consistent finding across weight‑loss trials is that whenever body weight is reduced, by diet alone, bariatric surgery, or medication, some proportion of the lost weight comes from lean body mass, not just fat. With GLP‑1 receptor agonists, body composition analyses indicate that, alongside significant fat mass reduction, there is also meaningful loss of lean tissue, including muscle and skeletal bones. The exact percentage varies by study, but it is clear that lean mass loss is an inherent part of rapid weight loss, especially when appetite is markedly suppressed and protein intake is not deliberately maintained.
Loss of muscle mass matters because skeletal muscle is a major determinant of metabolic health, physical strength, mobility, and healthy ageing. Lower muscle mass is associated with reduced resting energy expenditure, increased risk of frailty, impaired glucose handling, and worse outcomes in older adults. Women, particularly in peri‑ and post‑menopause, may be especially vulnerable to sarcopenia and bone loss when weight reduction occurs quickly without adequate resistance exercise and protein intake.
Some studies suggest that combining GLP‑1 treatment with structured exercise programmes, particularly resistance training, can help preserve lean mass and support bone health compared with GLP-1 treatment alone. This indicates that the drug itself is not the only variable; the lifestyle context and nutritional pattern around it are critical for long‑term well-being.
Micronutrient Deficiencies, Including Vitamin C
When appetite is significantly reduced, total energy intake can drop very quickly. In some real‑world accounts, people describe moving from 2,000–3,000 kcal per day to well below 800 kcal, sometimes with long periods of near‑fasting because they simply do not feel hungry. Prolonged low intake without careful dietary planning can lead to micronutrient deficiencies, including vitamins and minerals essential for immune function, skin and hair health, energy metabolism, and neurological function, as well as basic metabolic functions the body needs to function at baseline.
A recent review on nutritional considerations with anti‑obesity medications highlights the potential for deficits in iron, B‑vitamins, fat‑soluble vitamins and other micronutrients, particularly when people reduce not just portion size but also diet diversity. Emerging reports and commentaries have raised the possibility of severe deficiencies, such as scurvy, in extreme cases of restricted intake. However, systematic data are still limited, since the excessive use of the drugs is still somewhat of a recent trend. The principle remains straightforward: if you are eating very little overall and not prioritising nutrient‑dense foods, your risk of deficiencies increases.
This underscores the importance of ensuring that, within the smaller appetite “window” created by GLP‑1 medications, the foods chosen are as nutrient‑dense as possible. That means concentrating on vegetables, fruits, pulses, wholegrains, nuts and seeds, and including sufficient protein, rather than relying mainly on low‑nutrient snack foods or ultra‑processed options that provide calories but limited micronutrients. In some cases, targeted supplementation may be clinically indicated, based on blood tests and professional assessment.
Bone Health, GLP‑1s, and Weight Loss
Bone health is another area where the data are nuanced. Some experimental and clinical studies suggest that GLP‑1 receptor agonists may have neutral or even modestly beneficial effects on bone turnover markers and bone formation in people with diabetes, potentially via improved glycaemic control and direct actions on bone cells. However, weight loss itself, especially when rapid and accompanied by reduced mechanical loading, can contribute to decreases in bone mineral density over time.
A recent trial comparing exercise alone, GLP‑1 treatment, and combined therapy found that adding exercise to GLP‑1‑based weight loss attenuated negative changes in bone mineral density compared with medication alone. This reinforces the idea that the combination of a drug and its lifestyle context matters for skeletal health. For women in midlife and beyond, who are already at a higher baseline risk of osteopenia and osteoporosis due to declining oestrogen levels, preserving bone density during weight loss is especially important. Adequate protein, calcium, vitamin D, and weight‑bearing or resistance exercise are all key protective factors.
Hair Loss, Fatigue, Mood, and Emotional Adjustment
Beyond numbers on a scan or blood test, many people using GLP‑1 weight loss injections report experiences such as hair thinning, persistent fatigue, low mood, increased irritability, and a sense of emotional volatility. While more high‑quality research is needed to characterise these effects fully, several plausible mechanisms exist.
Hair loss can be associated with rapid weight loss, inadequate protein intake, iron and zinc deficiency, other micronutrient deficiencies, and physical stress. Fatigue and low mood may be influenced by reduced overall energy intake, deficiencies in key nutrients such as iron, B‑vitamins or omega‑3 fatty acids, changes in gut hormones and neurotransmitter signalling, and the psychological impact of a significant body change. It is also important to remember that people living with obesity often already carry a substantial burden of weight stigma, trauma, and chronic stress; rapid shifts in appearance and social response can trigger complex emotional reactions rather than simple joy.
Identity shock — feeling disconnected from a rapidly changing body, or struggling to integrate a new physical self with long‑standing internal narratives — is increasingly reported in qualitative work on bariatric surgery and significant weight loss, and there is good reason to expect similar phenomena with pharmacological weight reduction. This highlights the need for psychological support and space to process these changes, rather than just focusing on kilograms lost.
“Many people using GLP‑1 weight loss injections report experiences such as hair thinning, persistent fatigue, low mood, increased irritability, and a sense of emotional volatility.”
In a Nutshell
Weight-loss drugs can increase the risk of osteoporosis by reducing lean body mass, including bone tissue, especially during rapid weight loss. Key concerns include potential deficiencies in calcium and vitamin D, as well as mechanical unloading of bones. To mitigate this risk, individuals taking these drugs should focus on optimising nutrient intake, ensuring adequate calcium and vitamin D intake through diet or supplements. They may consider a new drug like bimagrumab in the future.
How weight loss drugs affect bone health
Loss of lean mass: Rapid weight loss, particularly with GLP-1 drugs, can lead to a loss of lean body mass, which includes both muscle and bone tissue, increasing the risk of osteoporosis.
Nutrient deficiencies: These drugs may increase the risk of vitamin D and calcium deficiencies, both of which are crucial for bone health.
Reduced mechanical stress: Less body weight puts less stress on bones, which may disrupt the normal process of bone turnover (removal of old bone and formation of new bone).
Strategies to protect bone health
Ensure adequate nutrient intake: Work with a healthcare professional to ensure you are getting enough calcium and vitamin D.
Calcium: Include dairy products, fortified alternatives, or consider a supplement if dietary intake is low.
Vitamin D: A daily supplement, ideally taken with a meal containing fat, can help support absorption.
Consider a potential future drug: Research is ongoing on additional drugs (another way big pharma ensures indefinite revenues), which have shown promise in animal studies for increasing bone and muscle mass while counteracting weight-loss side effects. Next, another drug will be created to negate the direct effects of that drug, and so on… Resulting in billions in revenues.
Important considerations
Long-term effects: The effects of newer weight-loss drugs on bone mass are not yet fully understood.
Fracture risk: Some studies have reported an increased risk of hip fractures among users of certain GLP-1 medications, implicating the importance of bone health.
Consult your doctor: Always consult a healthcare provider to discuss the potential risks and benefits of weight loss drugs and to create a personalized plan for managing bone health during treatment.
Why Medical and Nutritional Oversight Matter
One of the most concerning themes in current discussions is how often GLP‑1 weight loss injections are being used without comprehensive medical, nutritional, or psychological support. Reports from clinical commentaries and patient surveys suggest that many people obtain these medications via private clinics or online services with minimal screening, cursory advice, and little or no long‑term follow‑up. General practitioners and multidisciplinary obesity services are sometimes bypassed, either due to access issues, cost, or perceptions of stigma and judgment.
From a safety and efficacy perspective, this is far from ideal. Evidence‑based guidelines emphasise that pharmacological treatment for obesity should be integrated into a broader care plan that includes nutrition therapy, physical activity guidance, monitoring of metabolic and psychological parameters, and ongoing support for behaviour change. GLP‑1 receptor agonists are not designed to replace lifestyle interventions; they are intended to augment them. Without this structure, the risk of complications, rebound weight gain, and unresolved underlying drivers of overeating is higher.
Furthermore, these drugs were developed for people medically needing to lose weight. It was never designed for otherwise “healthy” people looking to become skinny, as the film industry often demands, or for people who think they must follow every trend set by A-list actors… and that they will look like them…
How to Protect Your Health If You Use GLP‑1 Weight Loss Injections
If you are already using a GLP‑1 medication for weight loss, or you are considering it, several science‑aligned principles can help you protect your health:
First, aim for structured medical oversight. Whenever possible, work with a clinician who understands obesity medicine and can monitor blood pressure, blood glucose, lipids, and relevant nutrient levels over time. Regular follow‑up allows early detection of deficiencies or adverse effects and supports rational dose adjustments.
Second, prioritise protein and nutrient density. Within your reduced appetite window, make each bite count. Emphasise lean proteins, pulses, dairy or fortified alternatives, vegetables, fruits, and wholegrains to support muscle maintenance and micronutrient status. If your intake is very low, discuss supplementation with a qualified professional rather than guessing.
Third, include resistance or strength‑based exercise if you are medically able. Even two to three sessions per week of bodyweight or resistance training can send a strong signal to preserve muscle mass and support bone health during weight loss. Gentle progression is key, particularly for inactive people.
Fourth, pay attention to your mental and emotional health. Rapid change in weight, appetite, and social feedback can be destabilising. Suppose you notice rising anxiety, low mood, or identity confusion. In that case, it is entirely valid to seek support from a therapist or counsellor experienced in body image, eating behaviour, or chronic illness. Psychological health is a core part of successful long‑term weight management, not an afterthought.
Finally, remember that weight is only one measure of health. Long‑term well-being depends on many factors: sleep quality, stress levels, meaningful relationships, a sense of purpose, physical capacity, and metabolic health. A number on the scale, even if dramatically lower, is not worth pursuing at any cost if other aspects of health are quietly deteriorating.
A New Era of Weight Loss, But the Fundamentals Still Matter
GLP‑1 weight loss injections represent a significant advance in obesity treatment science. For many people living with severe obesity and metabolic disease, they offer a clinically meaningful opportunity to reduce risk and improve quality of life. At the same time, they bring new challenges in nutrition, bone and muscle health, psychological adjustment, and responsible prescribing.
What has not changed is the fundamental truth that sustainable health is built on balanced, nutritious eating, regular movement adapted to each person’s ability, adequate rest, supportive relationships, and compassionate self‑care. Medication can be a powerful tool, but it cannot replace holistic support.
As use of GLP‑1 weight loss injections grows, the conversation must move beyond simple “for” or “against” arguments. The real questions are: under what circumstances do the benefits outweigh the risks? What safeguards and supports must be in place? And how can we ensure that people using these drugs are not left to navigate the physical and emotional consequences alone?
Those questions require input from clinicians, dietitians, psychologists, researchers, and people with lived experience. Above all, they need a shift from quick‑fix thinking to a long‑term, person‑centred approach where weight is one piece of the puzzle — not the whole story.
“Sustainable health is built on balanced, nutritious eating, regular movement adapted to each person’s ability, adequate rest, supportive relationships, and compassionate self‑care. Medication can be a powerful tool, but it cannot replace holistic support.”
Are you looking for safe weight loss strategies?
We have everything to set you on a new journey with scientifically proven programmes for sustained weight loss and no rebound weight gain. We encompass all aspects of your life, not just the extra weight.
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