Semaglutide

✓Key benefits

📈What to expect

Based on community reports and published research. Individual results vary significantly.

💊Dosing protocols

Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.

Overview

Semaglutide is a modified version of human GLP-1 (glucagon-like peptide-1), a hormone naturally produced in the gut after eating. Developed by Novo Nordisk, it is FDA-approved as Ozempic (for type 2 diabetes) and Wegovy (for weight management). Clinical trials have demonstrated average weight loss of 15–17% of body weight over 68 weeks - results that triggered a global conversation about the future of obesity treatment. Semaglutide has become one of the most prescribed medications worldwide, with supply shortages reported throughout 2023–2025.

⚙️How it works

Semaglutide mimics the GLP-1 hormone, binding to GLP-1 receptors in the pancreas, brain, and gut. In the pancreas, it stimulates insulin secretion and suppresses glucagon release (only when blood sugar is elevated, reducing hypoglycemia risk). In the brain, it acts on appetite centres in the hypothalamus, reducing hunger and increasing satiety. It also slows gastric emptying, making you feel fuller for longer. The molecule has been engineered with a fatty acid chain that allows it to bind to albumin in the blood, giving it a half-life of approximately 7 days (enabling once-weekly dosing).

⚡Side effects

📅Research history

Vendor ratings are based on community feedback and are not endorsements. Always verify third-party certificates of analysis (CoA) and check current Australian regulations before purchasing.

The muscle loss problem

One of the most significant concerns with GLP-1 agonists is muscle mass loss. In the STEP 1 trial, approximately 40% of weight lost was lean mass (muscle), not just fat. This is a major issue - muscle loss reduces metabolic rate, impairs physical function, and can contribute to weight regain after discontinuation. Strategies to mitigate this include resistance training (3–4x per week), adequate protein intake (1.6–2.2g per kg of body weight), and slow dose titration. Some practitioners recommend concurrent use of growth hormone secretagogues to preserve lean mass.

Tirzepatide: the next generation

Tirzepatide (Mounjaro/Zepbound) is a dual GIP/GLP-1 receptor agonist that has shown even greater weight loss results than semaglutide in head-to-head trials. The SURMOUNT-1 trial demonstrated average weight loss of 20.9% at the highest dose (15 mg) over 72 weeks, compared to semaglutide's ~17%. Retatrutide, a triple agonist (GIP/GLP-1/glucagon), is in Phase 3 trials and has shown up to 24% weight loss. The field is evolving rapidly.

Compounded semaglutide

Due to brand-name supply shortages and cost ($1,000+/month without insurance), compounded semaglutide became widely available from compounding pharmacies at significantly lower prices. The FDA has been actively regulating this space. In Australia, compounded semaglutide availability varies by state and requires a prescription. Always source from a licensed pharmacy and verify purity through third-party testing when possible.

References

1. [1]Wilding JPH, et al. "Once-weekly semaglutide in adults with overweight or obesity (STEP 1)." New England Journal of Medicine, 2021.
2. [2]Lincoff AM, et al. "Semaglutide and cardiovascular outcomes in obesity (SELECT)." New England Journal of Medicine, 2023.
3. [3]Jastreboff AM, et al. "Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1)." New England Journal of Medicine, 2022.
4. [4]Rubino DM, et al. "Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance (STEP 4)." JAMA, 2021.

Frequently asked questions

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