In this post, Nedeia asks: I LOVE humectants. I always use glycerin, sodium lactate, panthenol, urea, Na PCA, oats and wheat proteins, I just LOVE them in my products! But I guess I tend to over use them, because sometimes the gels I am using all of them into is sticky. I always use less than 2% glycerin, and I try to stay at 2% with all the other humectants. So, my question is: how much is too much? Should I keep all humectants at a 3% or maybe 5% in my recipe, in order to avoid the stickyness? So, I would very much appreciate your thoughts on that - maybe even a post on how sticky can humectants be, and what's a girl to do when she wants an overdose of humectants.
How much is too much when it comes to humectants? If you like using them, then use them! Stickiness is a personal thing - what I consider okay might be really sticky to you! One of my favourite foot lotions I found on the Dish forum uses 25% glycerin and I love it! Believe it or not, it's not that sticky, but it offers great moisturizing! My best friend and my mom hate it, but I love that foot lotion for those days when I need some serious moisturizing and hydrating of my feet! So it really is about personal preference. (And I admit that I'm a humectant junkie, also. I think you can see that from the recipes I write!)
Worried that your humectants are pulling water out of your skin in low humidity environments? Worry no more! Read this post - does glycerin draw water from your skin when the humidity is low?
Having said all of this, if you are worried by the stickiness of the product you've just made, turn to some of the lower stickiness humectants like panthenol, sodium lactate (no more than 2.9% in your product to avoid sun sensitivity), sodium PCA, or Hydrovance. (Click here for links to the posts on humectants!) If you want to use them in a gel, consider using something like 2% panthenol and 2% sodium lactate because this combination would be very effective but not sticky.
I've used carbomers and Amaze XT to make gels, and the carbomers are definitely less sticky than something like Amaze XT, but there's still a tiny bit of stickiness in there.
You mention that you like algae extracts - I've been playing with sea kelp bioferment and I'm finding this ingredient a little sticky. I think the only way to figure out what's making it sticky is to make a gel, then add one humectant, then another, then another until you figure out what is contributing to that sticky skin feel.
So the short answer is use as many humectants as you like. The long answer is to use non-sticky types of humectants to reduce stickiness. I hope I've answered your question!