How to tighten arm skin? (Photo)

I am not at all surprised by the lack of success with the expensive "bells and whistles" gizmos that you mentioned in the question, as these, like many of the so-called "next big thing" light and energy-based devices, are backed far more by marketing and social media hype than hard scienc. Sorry. On the other hand, HA skinboosters have been used for many years already with gratifying in Europe and the Middle East for improving skin quality and hydration and diminishing crepey skin. Restylane Silk was the equivalent a skin booster in the U.S. and now the FDA has finally come lumbering along to approve Juvederm's Skinvive (called Profhilo in Europe and The Middle East), a product that I was successfuly using already for these purposes for many years in my satellite practice in Israel, where it was regularity agency approved long ago. A microdroplet technique is most often used for crepey areas, such as on the arms. Typically a series of thee or four treatment sessions are required to achieve optimal improvement.

Interesting case. As to what caused the skin changes....many factors can affect skin....poor diet, hormonal changes(peri/menopause), dehydration, genetics, cumulative sun damage, smoking, etc. I think you have a couple of options. Treat the skin with hydrating serums/creams, protect against further sun damage, vitamins such as A &E, get hormones checked....estradiol (bioidentical) is great for the skin. Consider tightening the skin by using a transdermal approach....such as micro-needling RF or you could use something that tightens from underneath the skin like Renuvion or Bodytite. If this doesn't help then you could consider surgical options such as a brachioplasty....as long as you're ok with the scar. Hope this helps!

While this can be a tricky problem it can be treated with a comprehensive plan.
First, the most powerful microneedling RF devices on the market are the Morpheus8 and the sylfirm. The Morpheus8 has the advantage in that it goes a little deeper, and the Sylfirm’s advantage is it is the strongest of all of them.
At least three treatments would be recommended and highly suggest adding exosomes to your treatments. Underneath the skin you could consider using the bodyTite by Inmode to get some structural lifting, but it won’t help the crepiness of the skin. You should also consider powerful skin care just as you would, for the face and neck, such as retinol’s and exfoliators, but be careful to not irritate the skin too much. Use as much as you can without irritating the skin. And obviously wear a good SPF religiously.
Finally, one other unique technique is to use hyper dilute Radiesse in the entire area, develop a nice sheet of collagen.And of course, do you want to go to a practitioner that has experience with all of these modalities