Understanding the science, the history, the risks, and the realities behind the “miracle” injections
It is impossible not to have heard of the new trend in weight management and diabetes treatment. The surge of interest in so-called “skinny jabs”, injectable medications designed to help control appetite and blood sugar, has captivated many. Two classes of these medications, GLP-1 and GIP receptor agonists, have made headlines for their effectiveness, but they also come with plenty of myths and misunderstandings. Continue reading for a deeper understanding of what GLP-1 and GIP injections are, how they work, their medical history, the risks associated with them, and what to expect if you decide to discontinue treatment, as well as evidence-based methods to sustain weight loss over the long term.
What Are GLP-1 and GIP Jabs?
GLP-1 stands for Glucagon-Like Peptide-1, a hormone naturally produced in the gut in response to eating( but in its natural form, it is broken down quickly by the body). It stimulates insulin secretion, reduces glucagon release, slows gastric emptying, and sends signals of fullness to the brain, all of which lower blood glucose levels and reduce appetite.
GIP stands for Glucose-Dependent Insulinotropic Polypeptide, another gut hormone with similar but slightly different effects. Like GLP-1, GIP enhances insulin secretion after meals and plays a role in fat metabolism.
“Jabs” refers to injectable medications that mimic or amplify the effects of these hormones. The two are sometimes combined in one injection (as with tirzepatide, known commercially as Mounjaro), offering a powerful combination for blood sugar control and weight loss.
How Do These Jabs Work?
When you eat, your gut releases GLP-1 and GIP, preparing your body for the rise in blood sugar. These hormones:
- Increase insulin secretion from the pancreas (helping move glucose out of the blood and into cells)
- Suppress glucagon (which would otherwise tell the liver to release more glucose)
- Slow stomach emptying, making you feel full for longer
- Communicate with the brain to reduce appetite and cravings
GLP-1 and GIP agonists, delivered via injection, mimic or enhance these natural processes. This means they can lead not just to improved blood sugar control, but also significant weight loss, which is why they’ve become so popular for people living with obesity, prediabetes, or type 2 diabetes.
A Brief History: From Diabetes to Weight Loss
The story of GLP-1 agonists began in the late 1990s and early 2000s, when researchers observed that people with type 2 diabetes often had lower levels of GLP-1. The first GLP-1 mimetic, exenatide (Byetta), was approved in the United States in 2005 for the treatment of type 2 diabetes. Liraglutide (Victoza), another GLP-1 agonist, followed in 2010.
Soon after, patients and clinicians noticed that many of these drugs caused notable weight loss as a side effect. This led to clinical trials specifically targeting obesity, resulting in medications like liraglutide (Saxenda) and semaglutide (Wegovy/Ozempic) being approved for weight management.
GIP-based drugs are newer. Tirzepatide (Mounjaro), which activates both GLP-1 and GIP receptors, was approved for type 2 diabetes in 2022 and is now being studied and used for weight management.
So, while their development started with diabetes, their role in weight management has become increasingly prominent over the past decade.
The Hype and the Risks: Not an Easy Fix
It’s easy to see why GLP-1 and GIP jabs have been called “miracle drugs.” Clinical trials have shown that some individuals can lose up to 15-20% of their body weight with these medications, along with substantial improvements in blood sugar, blood pressure, and cholesterol levels.
However, they’re not without risks and side effects. The most common symptoms are gastrointestinal issues, nausea, vomiting, diarrhoea, constipation, and bloating. Some people experience heartburn or a profound decrease in appetite, making it difficult for them to eat enough, risking nutritional deficiency.
Less common but more serious risks include:
- Pancreatitis (inflammation of the pancreas)
- Gallbladder disease
- Possible increased risk of certain thyroid cancers (based on rodent studies, not proven in humans)
- Hypoglycaemia (low blood sugar), especially if taken with other diabetes medications
- Allergic reactions, though rare
These medications are not suitable for everyone. People with a history of pancreatitis, certain types of thyroid cancer, or who are pregnant or breastfeeding should avoid them.
The Risk of Losing Muscle Mass
One important consideration with rapid or significant weight loss, including that achieved through GLP-1 and GIP jabs, is the loss of muscle mass alongside fat. While these medications can be very effective at reducing body weight, not all of the weight lost is fat; research has shown that a portion can come from muscle. This is concerning because muscle is not only key for strength and mobility but also plays a critical role in maintaining metabolic health and a higher resting metabolic rate.
Regaining Weight: Why More Fat and Less Muscle Is a Concern
When people regain weight after stopping these medications, there is a tendency for the weight to come back as fat rather than muscle. This means someone could end up with a higher proportion of body fat, especially visceral fat, and a lower amount of muscle compared to before they lost weight. This shift in body composition can make maintaining weight loss even more challenging and can negatively affect metabolic health, increasing risks for insulin resistance, type 2 diabetes, and cardiovascular disease.
Having more adipose (fat) tissue and less muscle can lead to a slower metabolism, reduced physical strength, and poorer glucose control. This emphasises the importance of strategies to preserve muscle, such as resistance training and ensuring adequate protein intake, during weight loss, regardless of the method used.
What Happens When You Stop Taking GLP-1 or GIP Jabs?
Unfortunately, the effects of these medications don’t last forever. Several studies have shown that most people regain some, or even most, of the weight they lost if they stop the injections and don’t make lasting lifestyle changes.
Why is that? GLP-1 and GIP agonists suppress appetite and help your body regulate blood sugar better. When you stop, hunger often returns, cravings can intensify, and your body may adjust metabolically to regain lost weight , a phenomenon known as the “set point theory.” If you have lost muscle during your weight loss journey, the risk of regaining more fat and less muscle is even greater, making long-term weight maintenance and metabolic health more difficult.
Blood sugar may also rise, especially in people who were using these medications for diabetes management.
The Best Way to Maintain Weight Loss After Stopping Treatment
If you’ve used a GLP-1 or GIP jab and decide to stop , or if you can’t stay on it for medical or financial reasons , there are still effective strategies for maintaining your hard-won results:
- Prioritise whole, high-fibre foods: Fruits, vegetables, whole grains, and legumes are filling and help control appetite naturally.
- Include adequate protein in your diet: Protein helps preserve lean muscle mass during weight loss and supports a healthy metabolism.
- Keep moving: Regular physical activity, especially a mix of aerobic (walking, cycling) and resistance (weights, yoga) exercises, maintains muscle mass and metabolism.
- Track your progress: Regular weigh-ins and food/activity journals can help you spot patterns, triggers, or setbacks early.
- Set realistic goals and expectations: Weight naturally fluctuates. Focus on trends, not day-to-day changes.
- Seek support: Community, friends, family, or professional guidance, can make a big difference.
- Manage stress and sleep: Both can influence appetite and cravings.
Preserving muscle and preventing excess fat regain should be a top priority. The combination of good nutrition, resistance exercise, and mindful, sustainable habits will help support long-term metabolic health and successful weight maintenance.
Final Thoughts
GLP-1 and GIP jabs have transformed the treatment landscape for type 2 diabetes and obesity. They’re powerful tools, but not magic bullets. Understanding how they work, their risks, and the realities of long-term weight management will help you make informed decisions. Whether you’re considering these treatments or looking for ways to keep the weight off for good, the fundamentals of healthy living remain the same: balanced nutrition, regular movement, and self-compassion.
If you’re considering a GLP-1 or GIP jab, it is advisable to consult your doctor to discuss your medical history, risks, and what you can realistically expect. And if you ever decide to stop, know that with the right support and strategies, you can keep moving forward, one healthy step at a time.
