I'm a dermatologist- here are the cosmetic procedures I've had done that I regret and would never recommend to my patients

With seemingly endless options for expensive cosmetic procedures to enhance appearances, it's hard to know which ones are actually worth spending money on.

But Dr Charles Puza, a New York City-based dermatologist, offered advice to his nearly 2million TikTok followers on what he would and wouldn't spend money on.

In one TikTok video, the doctor highlighted three procedures he's had done himself that he 'regrets,' saying they are ineffective and not worth doling out the cash for.

They include cool sculpting, injectable moisturizer and facial threads. 

Dr Puza called the results 'disappointing' and not long-lasting and he even warned of potentially 'disfiguring' side effects.  

 Dr Charles Puza, a New York City-based board-certified dermatologist, revealed to his followers the cosmetic procedures he wouldn't waste his money on

First, Dr Puza talked about CoolSculpting, which is advertised as a non-surgical and non-invasive way to destroy fat cells in the body.

The procedure uses cryolipolysis to freeze fat cells and was FDA approved in 2010. It uses extremely cold temperatures, between 30 and 40 degrees Fahrenheit, to freeze the cells until they are naturally eliminated by the body over several weeks to months. 

Freezing the fat kills the cells and your body's immune system then clears them away, which leads to a permanent reduction of fat in the treated area.

But CoolSculpting isn't for everyone and will only be most effective on people with 'small amounts of pinchable, plump fat,' dermatologist Dr Paul Frank told Cosmopolitan. 

And it won't replace exercising and a healthy diet as it only helps to reduce small amounts of fat in targeted areas. 

Dr Frank said: 'So someone who has three pounds of pinchable fat to remove in one area will have better success with CoolSculpting than someone who has an excess of 10 pounds.'

CoolSculpting is advertised as a non-surgical and non-invasive way to destroy fat cells in the body, by Dr Puza said the results were 'disappointing'

Injectable moisturizer involves needling skin with hyaluronic acid, which increases skin elasticity, to boost hydration in the face

The procedure, which can cost between $1,200 and $2,500, can be done on the stomach, chin, love handle area, thighs, upper arms and chest. Even still, CoolSculpting will not have the same effects on everyone. 

Dr Puza said he had the procedure done on his lower back and love handle area two years ago. 

He called the results 'disappointing' and warned of a side effect called PAH - paradoxical adipose hypertrophy - which happens when the areas being targeted to reduce fat actually increase in size. 

Dr Puza didn't experience this himself, but supermodel Linda Evangelista has spoken about her experience with PAH after receiving CoolSculpting herself. She received seven sessions around her jaw, thighs, stomach and back.

However, the fat in those areas thickened and 'expanded into hard, numb bulges that rounds of liposuction and weeks in full-body compression garments could not remedy,' she told The Times.

The former supermodel has also described her 'nightmare' procedures as disfiguring. 

Next, Dr Puza, who works at MOMA Derm, talked about Skinvive, also called injectable moisturizer. 

Dr Puza said he tried injectable moisturizer but did not see a difference in his face so now he refuses to sell the product to his patients

Dr Puza said he only experienced the lifted effect of facial threads for a few weeks

The procedure involves needling skin with hyaluronic acid, which increases skin elasticity and hydration. The 'microdroplet injectable' is a fairly new concept and the FDA approved Skinvive last year.

Unlike facial filler, the injection does not plump skin, rather it only provides a boost of hydration for a 'radiant, hydrated appearance.' It can cost between $650 and $750. 

Dr Puza said he did this to himself and a friend and there was no difference in the quality or hydration of their skin. Now, he refuses to even offer or sell the product to his patients. 

Lastly, Dr Puza cautioned people about facial threads. He underwent the procedure in his jawline and upper face.

He said: 'While I instantly loved the lift and the contouring, it's not long lasting. Just a few weeks after the procedure I feel like the results are totally gone.

'So I can't offer that to my patients either.'

Facial threads, or thread lifts, are less invasive - and expensive - than a facelift that give saggy skin a lifted appearance. 

While full surgical facelifts can cost $10,000 to $25,000, thread lifts can run anywhere from $700 to $6,000 depending on location and amount. 

The procedure involves a surgeon placing small surgical threads under the skin that hold tissue to provide a tightening look. There is little to no downtime after getting the threads implanted and effects will continue to develop over several months. 

While Dr Puza saw his results fade quickly, doctors say the threads should last between one to two years until the sutures eventually dissolve.