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What should i avoid mixing

I'm more wanting to understand the chemical aspects in the products I have just purchased as I'm completely niave lost on anything in the aspects of what's good and not good to mix or how often to use. I rhave read little about Aha's and bha's that niacimide for example shouldn't be used together.. I'm so niave u may as well say I don't know what foundation is... just a joke. but certainly unaware of anything  like examples of products thus collagen peptides nicinamide vitamin c retinol hydronic acid hydrolic acid fulvic or squlane  acids polyglutamic acid aswell as lactic or folic acid and polyglutamic acid.  I just don't wanna mix a burn skin and need to k ow what I should be doing inorder to gain the bright youthful de wri kle look but I've got like q0 boxes here and on iris I can use all in one day at different times.. I need to know what a good start for a chemical Virginia fave would be I'm 40 yrs and am drastically ally showing more lines monthly.  If u could five me NY info o  mwhat u should h e or what I should be doi g be great.  L my products at the inkey list.  Plz any advice om lost in a candy store ND Don't wanna make a bad reaction mistake. Hope I'm not  bugging. I'm also looking for a good tint foundation that's like ysl but cheaper

Re: What should i avoid mixing

@jozeyah  Have you ever seen/talked with a dermatologist? A board certified derm is a good source of info on skincare ingredients, products, and routines. 


As for which things you shouldn't mix (er, layer), well... that kinda depends on your particular skin's tolerance of various ingredients. Some folks, like me, can layer an AHA exfoliant and retinol (or other vitamin A derivatives) with no trouble. But that's because I very gradually built up my skin's tolerance of both those ingredients over time before trying to layer them, plus my skin generally has no issue with either ingredient. Some people's skin simply can't tolerate those 2 ingredients layered over each other. Some folks are skin-sensitive to ascorbic acid (vitamin C) while others can use it with no issues. Some people are truly allergic to BHA (salicylic acid), which means there's a whole list of related ingredients they must avoid. 


Generally speaking though, since you mentioned niacinamide: that ingredient plays nice with just about everything. There's a myth about not mixing vitamin C and niacinamide, but that's been proven false. Those 2 ingredients won't counteract each other, and the only way layering them could cause a dangerous reaction is if extreme heat is applied. None of us do our skincare routines while sitting in a kiln, so we're safe from that. 


To learn more about various skincare ingredients, try one of these reference sites: 

We can't post links on BIC to sites outside Sephora (though youtube links might be okay), so you'll have to Google these. 

- a database where you can search for products or individual ingredients. It’s run by the co-founder of a skincare brand (Geek & Gorgeous), but I haven’t noticed any bias and the info seems soundly based on scientific studies. This site doesn’t provide product reviews. Rather, it lists a product’s ingredients (in different helpful formats) and defines many of those ingredients. 
Lab Muffin - a blog run by a chemistry PhD (who’s also now a cosmetic chemist) named Michelle. She also has a good Youtube series. This may be my own bias showing, but Michelle’s one of my favorite sources of skincare info from a science-based perspective. 
Paula’s Choice Skin Care Ingredient Dictionary - a dictionary of various skincare ingredients. This is obviously run by the Paula’s Choice skincare brand, and sometimes I see a bit of bias in the info provided. But Paula’s Choice does use scientific studies to back up their claims. 
Also, if you browse the Paula’s Choice site to shop for their own products, you’ll notice some of their ingredient lists include very brief notes about what each ingredient does. 
Beautypedia - a collection of product reviews. This site used to be run by Paula’s Choice and there’s definitely some bias in some of the reviews, so take what you read there with a handful of salt. But it’s a decent source of info when you want to know a product’s pros and cons. Note that the reviews aren’t dated, so some of them may be outdated since products may have been reformulated since the review was posted. I really wish they’d date their reviews. Also, I’m not sure if the folks behind Beautypedia are still actively reviewing newly released products. 

Various dermatologists on Youtube - I don't follow any of them, but there are some popular ones like Dr. Dray, Dr. Alexis Stephens, the Doctorly youtube channel run by 2 derms, Dr. Sam Bunting, and several others. The key here is making sure they're board certified derms, not just beauty influencers. 
I’m sure more folks can chime in with other helpful resources. 
I absolutely do not recommend “clean beauty” sites like the EWG (Environmental Working Group) as skincare info resources. The EWG is a hot mess of fear mongering and faulty science—if they base things on science at all. “Clean beauty” in general is nothing but a marketing scheme that preys on consumers' fear of unsafe ingredients. That’s a hill I’ll proudly die on. 😄 

Re: What should i avoid mixing

 I'll Def take a look thanks

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