63 lbs lost here and dealing with similar issues. Here's what I've tried and my honest assessment:
Things that actually helped (somewhat):
- Resistance training — building muscle underneath loose skin helps fill it out. My arms look significantly better since I started lifting. This is the #1 thing.
- Collagen peptide supplementation (15-20g/day) — jury is still out scientifically but I think it's helped my skin texture. At minimum it's a good protein source. I use Vital Proteins.
- Tretinoin 0.05% cream on face/neck — prescription retinoid, proven to stimulate collagen production. My derm prescribed it for "Ozempic face" prevention. Takes 3-6 months to see results.
- Adequate protein intake (>100g/day) — protein is the building block for collagen. Undereating protein while losing weight fast is a recipe for poor skin elasticity.
- Staying hydrated — dehydrated skin has less elasticity. Sounds basic but it matters.
Things that didn't help:
- Body wraps — complete waste of money
- Skin firming creams (drugstore brands) — did nothing detectable
- Dry brushing — felt nice, did nothing for loose skin
Things I'm considering but haven't tried:
- Red light therapy — some evidence for collagen stimulation, but the home devices are likely too weak to be effective
- Microneedling — my derm says it can help with skin texture but won't fix significant laxity
- Surgical options (abdominoplasty, brachioplasty) — the nuclear option. Probably where I'll end up for the abdomen.