Now I'm not an "expert" on cosmetic surgery (like Dr. Aston) but I am an expert on zefron. Therefore I'm not afraid to state my opinion... Zac Efron has not had a nose job and here I shall make my case.
Admittedly you can find 'damning' photo comparisons (such as the one at that website) or this one:
Obviously Zac's nose looks a lot wider in the first picture versus the second. So does that inevitably mean he had a nose job?
Let's compare two more pictures (helpful that he's actually smiling in both):
Okay. So in the first one his nose is wider in the second. So going by the standards of the aforementioned website that means he had a nose job between the first and the second picture.
Problem is the first picture is from May 2006 and the second is from March 2006. So he travelled back in time to do this nose job... Huh...
Clearly something else is at work. So now let's take that March 2006 picture and put it next to a more recent picture from January 2008:
There doesn't seem to be much of a difference to me.
Here's another sequence of three:
Again his nose seems smaller in the first pic than the second pic, but we know from the gap in his teeth, the first definitely happened before the second.
And as if that weren't enough, animation fun:
So how do we account for those pictures where is nose is wider? Think of your own nose and how many different ways you can make it look by smiling or inhaling versus exhaling and flaring your nostrils. That'd be my guess.
Not to mention he did a lot of growing up between here:
(see what I did there? obligatory ultra-hot picture. check.)
a few more comps:
Anyway. I'm sure we'll never know for certain. But whatever this killed some time for me and I've gotten it off my chest.
ETA: a few more comparisons for people