my marks were only 6 months old when i started to use trilastin and they were silvery white for about 4 or 5 months i believe. so not very long but believe it or not according to what they say about the product it's actually supposed to be MORE effective on older marks as opposed to newer ones. if you read some testimonials and look at before and after pictures you'll see that some of the people have had there marks for 20 yrs or more! also from what i've heard about vitamin e oil is that it's most effective before the marks occur not so much after. keep in mind i'm no expert but i have done my fair share of research about this stuff. if i were you i would definitly give it a shot! what have you got to lose...except some money but there is a money back guarentee...jeeze i feel like a spokesperson for them or something! lol i only speak so highly because i just finished my first tube of it and got a second one and i've been seeing GREAT results and i just want to tell everyone! i'm right there with you on the embaressment level only to be honest i would be HAPPY to have the stretch marks on the back of my knees because mine are located on my breasts and you can see them in a bikini and of course now its swimsuit season. usually i'm counting down the days till summer and being able to go to the beach but this yr was the first i actually dreaded it...such a terrible feeling to dread what you love most about life. but at least now after a month of using trilastin you can't see my marks in a bathingsuit. i've been using fake tanner to cover them up also which seems to work pretty good because i don't want to expose them to the sun too much and negatively effect my results...alright i think i've said enough! sorry that was quite the mouthfull. i hope this helps! and really give it a shot! i wish you the best of luck!