GLP-1s Explained: What Women Actually Need to Know Before Starting
Dokkcast Episode 8, with registered dietitian Marcela Fiuza
Few medications have changed the conversation around weight management as fast as GLP-1s. In episode 8 of Dokkcast, we welcome back registered dietitian Marcela Fiuza — part of our ongoing series on nutrition for women in their 40s — for a deep dive into what these drugs actually do, who they're really for, and why the medication is only ever "the front door" to lasting results.
What is a GLP-1, really?
GLP-1 is a peptide your body already makes. It's released in the gut after eating, and it does three things: signals the brain that you've had enough, prompts the pancreas to release insulin, and slows gastric emptying so you feel fuller for longer. The catch is that your natural GLP-1 only lasts a few minutes in the bloodstream.
The medications now widely used — semaglutide (Wegovy) and tirzepatide (Mounjaro) — are engineered versions that bind to the same receptors but last around a week per dose. That extended action is what drives the dramatic reduction in appetite and "food noise" that many people on these drugs report.
The numbers are striking
Marcela walks through the trial data: semaglutide users saw around 15–16% weight loss, while tirzepatide's dual-receptor action pushed that to 20–22%. A newer triple-agonist drug currently in phase 3 trials — which also targets glucagon receptors — is showing results as high as 24–28%. For context, that's approaching outcomes previously only seen with bariatric surgery, but through a far less invasive route.
Who are they actually for?
This is where nuance matters. The trials that established safety and benefit were run on people living with obesity (BMI above 30) or who were overweight (BMI above 27) with an existing weight-related condition like type 2 diabetes or cardiovascular disease. For that group, the benefit clearly outweighs the risk. Outside that population, the evidence is thinner — which is exactly why access via the NHS is tightly criteria-based, while private access opens up a much wider (and murkier) landscape.
The part that gets skipped: wraparound care
Marcela's clearest message is that the medication is never the whole plan. Prioritising a nutrient-dense diet, adequate protein, and resistance exercise before, during, and after starting therapy is essential — and it's far harder to get right alone. Her advice: choose a provider that offers genuine wraparound support, whether that's a dietitian or a trained nutrition coach, not just a prescription dropped in the post.
On the subject of self-directed "microdosing," she's direct: going off-piste from a licensed dose isn't supported by any safety or efficacy data, and it's not worth the risk.
The bigger picture
The episode closes on something rarely addressed head-on: self-image. Marcela speaks candidly about the genuine confidence and behaviour-change benefits many people experience — and the darker undercurrent of shrinking bodies being normalised again across media and culture, and what that risks for anyone already vulnerable to disordered eating.
As Marcela puts it, the medicine is the front door. What you build once you're through it — nutrition, movement, mindset — is what actually lasts.
Listen to the full episode of Dokkcast for the complete conversation, including how GLP-1 access differs across the NHS and private care, and Marcela's practical advice for anyone considering starting.
