Crepey, saggy skin on upper thighs and arms after cancer. Best solution for skin tightening on arms? (Photo)

So glad to hear that you are in remission. The crepeyness you exhibit is quite commonly seen when there is muscle and fat volume loss from any cause. Unfortunately, the supposed benefits of treatments wit all too many of the expensive, bells and whistles light and energy-based devices out there are more the substance of media hype and social media buzz than actual hard science. So, exercise a whole lot of "buyer beware" when evaluating these.
You might wish to consider the use of injectable HA skin boosters or biomodulator injections intended to help to naturally promote the production of new collagen and new elastic fibers (neocollagenesis and neoelastogenesis). Typically a series of injection sessions would be needed to achieve optimal results. You would be wise to consult an experienced board certified cosmetic dermatologist injection expert.
Best of luck and Happy Thanksgiving.

Thank you for sharing your experience — and truly, congratulations on being in remission. Your body has been through so much, and the changes you’re noticing are incredibly common after major weight or muscle loss, especially during and after cancer treatment. None of this is your fault, and there are ways to help the skin look and feel better over time.

From your photo and description, the crepiness on the upper arms seems to be a combination of skin laxity, decreased collagen, and reduced muscle support underneath — all normal after illness, weight shifts, and limited mobility.

Here are the options I tend to find most helpful for this specific combination:

1. Energy-based skin tightening treatments
These are some of the most effective when exercise is limited. They work by stimulating collagen and elastin in the deeper layers:

Radiofrequency (RF) devices (Morpheus8, Profound, Thermage)

RF microneedling, which can give more dramatic tightening in thinner skin

Ultrasound-based tightening (Ultherapy)

These gradually improve firmness and texture over several months.

2. Biostimulatory injectables
Products like Sculptra or hyperdilute Radiesse can be placed into the arms to thicken crepey skin and improve elasticity. They don’t “fill” the arms as much as they rebuild collagen.

3. Topical support
While topicals won’t tighten the skin alone, they help enhance and maintain results. Look for:

Retinol or retinoids

Collagen-supporting ingredients like peptides

Fragrance-free moisturizers to keep the skin barrier strong

4. Gentle strengthening, even with limited mobility
Though you mentioned nerve damage limiting movement, even very small-range resistance exercises, isometric holds, or working with a physical therapist can gradually increase tone without overstraining.

Just know this: the skin changes you’re seeing are a completely normal part of recovery, and they can improve. Many of my patients in similar situations see meaningful tightening with a combination approach.