Use the lowest peroxide level you can to get the job done.
Understand that lightener takes 15 minutes to move the natural pigment from one level to the next, so 15 mins. for a natural level 4 to go from the 4 to a 5, then 15 more minutes to get from a 5 to 6 and by the time you get to a level 7/8 it will take 20 minutes to go from that level 7 to an 8 and once the red pheomelanin is gone from a level 8, you will only have gold pheomelanin to deal with, so patience is needed since it normally takes 45 minutes to 1 hour or more to go from an NL-4 to a pale blond level 9.
Use Olaplex #1 in your lightener, it takes the sulfate group SO3 and prevents it from forming cysteic acid which is what eats protein out of the hair, Olaplex works to prevent this from happening.
HIGHLIFT VERSUS LIGHTENER-
Highlift color versus lightener-
Highlift color + double 40vol is more damaging than lightener + 20vol. BUT….
Any lightener can become dangerous if it is left on the hair too long or put over compromised hair, so make sure you stop at pale yellow, the inside of a banana yellow, the part you eat. Going beyond this will cause the cortical fibers to start to break down making the hair unstable.
After coloring or lightening, rinse very well and then use a Olaplex #2 for 10 to 20 minutes and follow that up with a protein/ moisture / Ceramide product like the Redken Extreme Maski, which has the perfect amounts of the different sizes of protein, (think boulders, rocks, pebbles, and sand), some proteins are way too big or too small to help the hair, their molecular weight won’t help it, but Redken’s, Joico’s and Matrix all have good ones that helps put everything the hair needs to tighten up and smooth the cuticle layers down.
Use a Leave-In Conditioner, this acts as an acidifier to help tighten down the cuticle layers sealing all the goodness you put in.
Then use an Argon product, which is a great way to seal & protect the cuticle, it’s a natural heat protectant and mimics the “f” layer which is lost whenever any chemical is used on the hair. I like the Olaplex #7 Oil, its very lightweight even on fine hair.
So there are some pointers for you.
-Mags Kavanaugh AskMags.com, a Stylists 911