Know your injection series

A few weeks ago, I was on the hunt to buy a bicycle for my children. I spent hours researching different bikes on the market: what was good, how they worked, what parts they had, and what they were missing. I looked at reviews, read opinions, and watched videos. After countless hours, I finally settled on a bike, and it was loved by my child.

This got me thinking—do we spend as much time, effort, and energy researching the medications we put into our bodies? Do we read the science? Do we trust our doctors? And what about situations where there isn’t a doctor involved—just a computer screen and a questionnaire? Can we trust that?

This series is specifically focused on weight loss drug injections. We’re not here to provide medical advice—that’s your prescriber’s job. We’re not here to sensationalize. Our aim is simple: to share what we, as doctors, have learned and observed, and to educate you.

We want you to know your injection.

GLP-1

Let’s be frank. When you drank your first coffee, had your first alcoholic drink, or smoked a cigarette, you probably didn’t do much research. You might have asked how it feels. You may have been nervous. Perhaps you tried it with friends. But it’s unlikely you looked into the biochemistry of how these substances affect your body or mind. And that’s normal.

So, why would we expect anyone to research weight loss injections—or any drugs, for that matter? We don’t, and you shouldn’t feel pressured to. But because we’re a little bit geeky, we like to dig into these things. Sometimes, understanding what these hormones do can help you better understand how they’re affecting you.

What is GLP-1?

GLP-1 (Glucagon-Like Peptide-1) is a natural hormone your body produces, mostly in your gut, when you eat. It helps regulate blood sugar levels and appetite. Here’s how it works, in simple terms:

1. Helps Control Blood Sugar:

After you eat, GLP-1 signals your pancreas to release insulin (which lowers blood sugar) and reduce glucagon (a hormone that raises blood sugar). This keeps your blood sugar stable.

2. Slows Down Digestion:

GLP-1 makes your stomach empty food more slowly into your intestines. This helps you feel full longer and prevents sudden spikes in blood sugar.

3. Reduces Appetite:

GLP-1 also sends signals to your brain to help you feel full, so you eat less.

Sounds amazing, doesn’t it? A hormone that your gut secretes after eating that regulates your blood sugar and tells your brain you’re full. However, the hormone itself is very quickly broken down and cleared from your system—within two minutes! And yet, that’s enough time for it to act upon the GLP-1 receptors.

The hormone was first discovered in the 1980s, but due to its rapid clearance, it was initially impossible to use it as a medicine. Fast-forward a few decades, and pharmaceutical companies managed to create a synthetic version that acts on the same receptors—but more about that in our next blog.

One of the biggest benefits of GLP-1 medications is their impact on blood sugar. In fact, they were first used as diabetes treatments before gaining attention for weight loss. But to understand how they work, let’s explore what blood sugar does in the context of fat gain:

1. Blood Sugar Spikes and Insulin Response:

• After consuming high-sugar or high-carbohydrate foods, blood sugar levels rise.

• This triggers the release of insulin, a hormone that helps cells absorb glucose for energy or storage.

• Excess glucose is converted into fat if not immediately needed, contributing to weight gain.

2. Frequent High Blood Sugar Levels:

• Chronic high blood sugar can lead to insulin resistance, where cells become less responsive to insulin.

• This causes higher insulin levels, promoting fat storage (especially around the abdomen).

3. Low Blood Sugar and Cravings:

• Rapid drops in blood sugar after a spike (reactive hypoglycemia) can trigger hunger, leading to overeating.

• Cravings, especially for sugary or carb-rich foods, can lead to consuming more calories than needed.

4. Impact on Energy Levels:

• Fluctuating blood sugar levels can cause energy crashes, reducing physical activity and calorie expenditure.

• Stable blood sugar levels support consistent energy, helping with sustained activity and better weight management.

5. Metabolism and Hormonal Effects:

• Imbalanced blood sugar disrupts other hormones, like cortisol, which can further promote fat storage.

• Over time, poor blood sugar control can affect metabolism, making it harder to lose weight.

We Want to Hear From You

We’re always keen to know your thoughts! Drop a comment below, and we’ll do our best to answer your questions (when we’re not seeing patients).

Please note: We cannot offer medical advice in this series. It is for informational purposes only. If you need personal medical advice, consult your GP or contact NHS 111.