You started a GLP-1. The weight is coming off.
Here’s what most people don’t know until it’s too late: a significant portion of what you’re losing isn’t fat. It’s muscle.
Research shows 25-40% of weight lost on GLP-1s is lean mass — muscle, bone, and organ tissue. For women in their 40s who are already at risk for sarcopenia and osteoporosis, this isn’t a side note. It’s the most important thing you need to manage.
The good news: it’s largely preventable with the right protocol.
The Non-Negotiables
Resistance Training
Three times per week minimum. Heavy compound movements — squats, deadlifts, rows, overhead presses. Progressive overload. This is the primary driver of lean mass preservation. Nothing replaces it.
Supplement Recommendation
I order everything through The Village Library’s Fullscript dispensary — professional-grade, up to 20% off retail. Same brands used by integrative physicians.
Protein Intake
Target 0.7-1g of protein per pound of body weight per day. On a GLP-1, your appetite is suppressed — which makes hitting protein targets harder. Track it intentionally. Prioritize protein at every meal before anything else.
The Supplement Stack
Creatine Monohydrate — 3-5g/day
The most well-studied supplement for muscle preservation and building. Stanford research also cites benefits for perimenopausal mood and cognitive function. No loading required — just 3-5g daily, consistently.
Creatine Monohydrate on Amazon →
HMB (Beta-hydroxy beta-methylbutyrate) — 3g/day
Reduces muscle protein breakdown — exactly what you need when in a caloric deficit. 2025 meta-analysis confirms significant benefits for muscle quality and body composition. Particularly valuable for women who can’t yet train at high intensity.
Protein Powder (as needed)
If you’re struggling to hit protein targets through food alone — common on GLP-1s due to reduced appetite — a high-quality protein powder fills the gap. Whey isolate or a complete plant-based blend.
Vitamin D3 + K2
Bone density is at risk on GLP-1s for the same reason muscle is — the mechanical loading that protects bone decreases as you lose weight. D3 + K2 supports bone mineralization. Get your level tested.
Collagen Peptides
Supports joint health, skin integrity, and bone matrix. As you lose weight rapidly, skin and connective tissue need support. Take with Vitamin C for best absorption.
Track Your Body Composition
The scale doesn’t tell you whether you’re losing fat or muscle. The Oura Ring tracks HRV and recovery — indirect markers of whether your body is managing the stress of weight loss well. For direct body composition tracking, ask your doctor about a DEXA scan or InBody assessment.
Shop Oura Ring 4 → (affiliate)
For Professional-Grade Supplements
Fullscript offers the same supplement brands used by integrative physicians — at practitioner pricing, with quality assurance. Worth exploring for your ongoing supplement needs.
Related reading:
- GLP-1s: What Every Woman Should Know Before Asking Her Doctor
- The Bone Density Crisis Nobody Talks About Until It’s Too Late
- The Supplement Conversation Every Woman in Her 40s Should Be Having
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The information in this post is for educational purposes only and does not constitute medical advice. Please consult a qualified physician for guidance specific to your situation. Some links are affiliate links — see our full Affiliate Disclosure.