This thickener worked to make my hair appear and feel thicker the very first time I used it. I have continued to use it for a week now and I do not see any significant additional improvement. But the product works so well and works instantly, so I will continue to use it whether or not it has the long-term effects that Pantene claims. I am really wild about this product and thrilled that for me it has no negative effects -- no stickiness, no flaking, no build-up, no damage to my hair. When I use it along with the Pantene AgeDefy Conditioner, my hair feels really thick and luxurious. When I use it with my Clear Scalp & Hair Therapy Strong Lengths conditioner, my hair gets great shine from the Clear conditioner and great body from this Pantene Thickening Treatment. I would say the thickness is greater with the Pantene Conditioner and the shine is greater with the Clear Conditioner. I alternate so I can enjoy both. I have been disappointed to see the price of this Thickening Treatment skyrocketing from $18.99 to $24.99. If it continues to rise, I may not repurchase even though I like it so much.