Size Doctor Extender Review

Update – Size Doctor Extender is no longer in business and the only devices left on the market are from 3rd party sellers. Please stay away and choose something better that is still supported on our list of penis extenders

Size Doctor Extender Review score:
  • Efficiency
  • Comfort
  • Build quality
  • Support
  • Price

Review summary:

I’ve just had the “pleasure” of testing it for 2 months and I’m finally ready to give it my full review.

The Size Doctor Extender is a device you mount on your penis and it will pull longer and longer over time. It has quite a few flaws in its design and I would not recommend it.

Its tension springs are quite weak compared to the competition which makes it a much less effective option.

It does have a few cool things going on for it but nothing that makes it worth a purchase in my mind. There are simply way better options available which are priced roughly the same.

You’re way better off getting the budget version of the Quick Extender Pro which can be yours for less than $100!

Size Doctor Extender Review

What I Think About It:

  • Very comfortable to use
  • Not very effective
  • Things tend to break easily
  • Very hard to get on/off

I can’t recommend the Size Doctor Extender; the quality and strength are simply not there!

User Review
0 (0 votes)

Update – Size Doctor is no longer in business and the only devices left on the market are from 3rd party sellers. Please stay away and choose something better that is still supported on our list of penis extenders

Full Review of the Size Doctor Extender

I’ll take a closer look at the Size Doctor extender, a popular device that promises to help you achieve your desired length and girth. With so many products on the market claiming to deliver impressive results, it can be difficult to separate the genuine contenders from the gimmicks.

That’s where I come in! In this comprehensive review, I’ll explore the Size Doctor’s design, functionality, and effectiveness, as well as share real user experiences to help you make an informed decision. So, sit back and get ready to discover whether the Size Doctor penis extender is the right choice for you.

Let’s Have a Look at the Extender Itself

My Size Doctor Extender came in a plain cardboard box but you can get a version in a wooden box, the content is the same but it’s just priced much higher.

The box contains:

  • The Size Doctor device itself
  • Lots of extra rods to extend the length
  • 6 Different sized silicone penis sleeves
  • A ball-pump and a stop valve
  • Instructions
whats in the size doctor box

Testing it

The initial setup looks pretty simple in the instructions but I had a really hard time getting the silicone sleeve mounted to the “head-holder” on the Size Doctor Extender. It was super hard to get it over the sealing rim and there was very limited space to work with.

Guess what happened when I finally got it on? It was the wrong size and I had to redo the whole ordeal. It’s really hard to determine the right size of silicone sleeve before it’s on the device.

My problems did not end there; the largest of the sleeves had an open rift in one of the bends which made it completely useless.

It looks like a general problem with this design as some of the other sleeves look weak in those bends.

It’s finally time to use it! Getting my penis in the “penis head housing” was easy once I applied a healthy amount of lube on my glans and the silicone sleeve. It’s simply not getting in there without lube!

Add the valve and the ball pump on the end of the head chamber and squeeze on the pump which creates a vacuum in the head chamber that pulls your penis in.

penis in size doctor

There is a gap in the black base which is pressed down around your penis while the device is squeezed together. Slowly release the pressure on the springs and let the extender extend your penis.

You should feel a pull on your penis that’s not painful but you should be able to feel it for it to have any effect on your penis length.

The pulling effect is pretty good but nowhere near the strength of devices like the Quick Extender Pro and the SizeGenetics.

I do wish that they would have included some way of tightening up the pulling strength while you have it on. It’s such a hassle to get it set up in the first place and doing it a second time to add extra rods is such a downer!

Thoughts About the Design

I generally love the idea of the mounting mechanism used in the Size Doctor Extender but after testing it for 2 months it’s clear that it has its downsides:

  • Starting with the grey silicone sealing sleeves – They are damn near impossible to get on and forget about it if you have the tiniest amount of lube on your fingers. I found the best way to get them on is to completely invert them and then force them on the entire ring at the same time.
    A large part of the problem is the spring holder that is crammed right up against the ring that holds the sleeve in place.
  • No adjustment options when it’s on – This is seriously a big problem since it’s so hard to get on in the first place. I was super frustrated when I finally got it on the first time only to discover that the rod length setup that I used was a little too short. A simple twist to extend function like the one on the Quick Extender Pro would have been amazing.
  • There is no tool for changing rods – You solely rely on your finger strength when it comes to changing the rods and they tend to kind of grow together after a while. No, don’t even try to get them off each other if you have the slightest amount of lube on your fingers.
  • Lack of quality – I have mixed feelings about the quality, on the one hand, it’s made with lightweight aluminum which is a huge plus but the plastic parts and silicone parts have general design flaws that make them fail pretty quickly. One of the silicone sleeves was even broken straight out of the box…
    broken silicone sleeve
  • Tension rods get jammed – I found this to be a common occurrence when I tried to press the springs back. It’s like the aluminum rods hit the brass part where the spring starts. The only way to completely avoid this is by making sure that you compress it with the same force on both springs at the same time. This is super hard to do and it will happen no matter how precise you try to do it.


  • It’s comfortable to wear
  • It has super long springs for a nice gradual increase in strength
  • It’s made with lightweight materials


  • The silicone sleeves break quickly
  • It’s really hard to get on/off
  • No adjustment options once it’s on
  • Not enough pulling strength

My Final Thoughts About the Size Doctor Extender After 2 Months

It would be a complete lie to say that I enjoyed using the Size Doctor Extender. It’s such a hassle to get on and off and the cleaning is a nightmare due to lube getting everywhere.

It does however feel pretty good to wear and comfort is a huge deal when you’re talking about wearing it for long periods of time.

But there are simply better options available so I can’t really recommend it to anybody even if you can find it cheap on some 3rd party sites. The problem with shopping for anything on these sites is that you risk getting counterfeit products that lack the quality control that the real deal has.

Picture of Austin Hanson, M.D. Urology

Austin Hanson, M.D. Urology

After finishing a master degree in Urology at the European University in St. Petersburg, Austin cofounded in 2015. The purpose of the website is to help men with a wide variety of sexual problems with a language that everybody understand. Austin is a dedicated writer and loves to get his hands dirty with product reviews and the latest urology news. You can read more about me on my profile at Austin's author profile.

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