Why you shouldn’t use weight loss injections without a prescription

Gastrointestinal issues are common side effects of weight loss injections. Many people taking them will likely experience nausea, vomiting, diarrhoea or constipation. These effects tend to be mild and subside as your body adjusts to the treatment. While they might amplify after each dose increase, they’re usually tolerable.

The side effects themselves don’t tend to be worse if you’re a healthy weight, but the consequences of those side effects can be greater. For example, a lean person struggling to eat food due to persistent nausea can mean a larger share of their energy stores is used up more quickly as opposed to someone with obesity. As their body begins to use these energy stores, they may lose a greater proportion of their body weight, including muscle mass, and become malnourished more quickly. This can make them feel weaker and tired.

In contrast, someone with obesity has larger energy stores, so while they can also become malnourished, it takes longer for this to happen.

Malnourishment can be a problem with GLP-1 injections, and using them at a healthy weight only increases the risk of this occurring.

When you lose weight, muscle loss is something of an inevitability, especially if you don’t resistance train or increase your protein intake. And while this isn't always a big problem, it can cause issues when your muscle mass is low to start with. People with lower body fat levels may be at greater risk of losing muscle because they have less stored fat. This can lead to muscle weakness and reduced physical function. In older adults, rapid weight loss and excess muscle loss can worsen sarcopenia, the medical term for age-related loss of strength and muscle.

Symptoms of sarcopenia include muscle weakness, slower walking speeds, difficulty rising from a seated position, reduced grip strength, and poor balance. If sarcopenia remains unmanaged, it can become serious and lead to physical disabilities and frailty.

It’s highly recommended to follow a high-protein diet and engage in regular strength-training exercises to help prevent too much muscle loss.

If you’re not eating enough (due to nausea or other side effects like vomiting), your body isn't getting the nutrients it needs to survive. This can lead to malnutrition, which can cause you to feel too tired and weak to perform even simple tasks. If you continue to struggle with eating and lose even more weight, you can become severely malnourished and underweight, which may result in hospitalisation.
Other side effects you might experience if you struggle to eat sufficient food include:

• Electrolyte imbalances: Low levels of potassium and sodium can cause heart palpitations and dizziness.
• A weakened immune system: This leaves you highly vulnerable to diseases and can prolong healing.
• Loss of brain function: A nutrient-deprived brain can lead to brain fog, headaches, and mental health issues.
• Hair loss: Your body prioritises essential functions over non-essential ones, meaning it may use limited nutrients for vital functions rather than for hair growth.

Additionally, if your body can’t get energy from food, it gets its energy from other sources, including muscle stores. Your body will draw nutrients from your muscles, potentially resulting in sarcopenia. And if you're a lean person, you'll have less energy stored than someone with obesity, which means you'll lose muscle faster.

If your appetite is suppressed and you experience side effects, you might drink less water, which can cause dehydration. Vomiting and diarrhoea can also contribute to dehydration. While mild dehydration can be concerning, it doesn’t require medical attention. You may feel tired, dizzy, and experience headaches. But if you're consistently dehydrated, it can become serious and lead to complications such as kidney failure and extreme dizziness, which will require urgent medical attention.

If you're taking weight loss injections unprescribed and without the supervision of a doctor, you're at a higher risk of serious complications, such as pancreatitis and gallbladder issues. Typically, your progress is monitored throughout your treatment to check that everything is okay, but without proper medical oversight, your health could be affected without you realising it.

Taking weight loss injections at a healthy weight can cause disordered eating and low self-esteem. 

People who struggle with body image issues might misuse weight loss injections to achieve their ‘ideal’ body type, rather than as an obesity treatment. Sometimes, this can lead to an unhealthy weight or conditions like anorexia, which can be very dangerous. This can turn into other health complications such as acidosis (low blood pH level), which has been reported in anorexic people using GLP-1 injections.

Weight loss injections can also trigger self-image issues and body dysmorphia. Without the supervision of a clinician, these issues can worsen. 

Additionally, they may lead to disordered eating habits, such as purging, bulimia, or binge eating, especially in those who already have these conditions. These issues can't be treated with medication alone; they often require several rounds of therapy and consistent behavioural changes. It’s important to address these issues early on to prevent them from becoming long-term problems that could negatively impact your physical and mental health.