Can You Add Shampoo, Conditioner or Olaplex to Bleach?

To make bleach milder, makers' directions offer a lower developer from their own list and a ratio inside their stated range; a deliberately diluted mix is a bleach bath. We found no professional lightener directions that include shampoo, conditioner or water. Bond builders such as Olaplex No.1 go in at their maker's dose, unless the lightener's directions caution against it.

Every "we found no" below means we searched and found nothing, not that nothing exists. "Lift" means how far the hair lightens, counted in levels.

At a glance

How to dilute bleach (make it milder) without adding anything

Makers' route to a milder mix is the developer and ratio they already list:

• Pick a lower developer from the maker's list. Wella mixes BlondorPlex with Welloxon Perfect 1.9%, 4%, 6%, 9% or 12%. Schwarzkopf lists BlondMe Premium Developer at 2% (7 vol), 6% (20 vol) or 9% (30 vol), with 9% for off-scalp use only (where the lightener doesn't touch the scalp). The % (hydrogen peroxide strength) and the "vol" figure are two names for the same developer: 6% is 20 vol. Schwarzkopf's BlondMe service manual claims Premium Lightener 9+ gives up to 3 levels of lift with 2%, up to 6 with 6% and up to 9+ with 9% (off-scalp only), and its own tip for "most gentle lightening and perfect control" is the 2% developer; these are the maker's "up to" figures, not measurements. A level is one step on the 1–10 dark-to-light scale colourists judge by eye, not a lab unit.
• Stay inside the maker's ratio range. A ratio is powder to developer: 1:1.5 is, for example, 30 g powder to 45 g developer, the amounts Wella's Wellaplex sheet uses. BlondorPlex mixes 1:1.5 or 1:2, and Wella says "DO NOT MIX 1:1 WITH DEVELOPER". BlondMe Premium Lightener 9+ mixes 1:1.5 to 1:2.5. L'Oréal's Blond Studio 9 runs from 1:1 for open-air techniques (balayage left uncovered) to 1:2 or 1:3 on the scalp. None of these makers says how much lift changes across its ratio range.
• On the scalp, 20 vol is the ceiling. No lightener maker we checked (Wella, Schwarzkopf, L'Oréal, Goldwell) allows more than 6% (20 vol) on the scalp; Olaplex's 2015 FAQ also recommended not going above 20 vol on the scalp, giving irritation as its reason, though it left higher volumes "at your own discretion" (the lightener makers' pages we read give no reason). The law in Great Britain caps hair products at 12% (40 vol) hydrogen peroxide; that is a legal limit for the product, not a target. The law has no separate on-scalp limit: the 20 vol ceiling comes from the makers' directions.
• Keep to the maximum time, with no added heat. BlondorPlex: "Do not exceed the maximum time of 50 minutes." Blond Studio 9: up to 50 minutes. BlondMe 9+: 20–45 minutes "without the use of artificial heat".

Apart from one small study, we found no study comparing 3%, 6%, 9% and 12% for damage under matched conditions. That study (Kim & Chun, 2005) used one donor's hair and one lightener, which cut the force needed to break the hair more at higher strength and longer time: stronger and longer left the hair weaker. Milder isn't free either: in the same study the gentlest setting, 3% for 10 minutes, did not lighten satisfactorily by eye. If you want a deliberately diluted mix, that is a bleach bath, which is a separate technique.

Can you add water to bleach?

We found no lightener maker direction that includes it, and Vitta Gold, a Brazilian hair brand, lists water among the things not to add. Salon lightener contains three active parts: hydrogen peroxide from the developer, and persulfate salts plus an alkali in the powder. Anything with no peroxide, persulfate or alkali dilutes them by its own share of the bowl (our arithmetic). The only in-bowl water data we found are company-patent control samples with no undiluted mix to compare, so we found no measurement of whether added water costs lift.

Can you add shampoo to bleach and developer?

Not for a normal lightening service: no professional lightener directions we found include it, and a lightener, developer and shampoo mix is a bleach-bath recipe. One consumer home kit, The Shade & Co, tells users to mix shampoo into the powder and developer, and hadviser.com's bleach-bath recipe does the same. We found no measurement of how much shampoo changes lift.

Vitta Gold's blog says not to add "shampoo, conditioner, oils, random bond products, water", because "These shortcuts can interfere with lift, alkalinity, stability, and predictability." That is the brand's advice, with no measurements.

• Lighteners already contain cleansing agents. Anionic surfactants such as sodium lauryl sulfate are normal ingredients of full-strength lighteners and developers. That says nothing about extra shampoo.
• Shampoo pH varies widely. A 2014 survey of 123 retail shampoos in Brazil found pH from 3.5 to 9.0 (not a UK sample). Mixed lightener is reported at about pH 9.5–11. You can't work out the bowl's pH from the two numbers, and we found no published measurement of a bleach bowl's pH after adding shampoo, so a shampoo's label pH doesn't tell you what it will do in the bowl.

Can you add conditioner to bleach?

No source shows it makes bleach gentler, and we found no data on retail conditioner in a bleach bowl. The nearest result is a Kao patent (EP2191812) where a little cetrimonium chloride, a conditioning-type ingredient, gave the same lightness reading as water, but with 9% developer for 40 minutes at 50 °C: added heat every lightener maker above says not to use, so it's a lab set-up, not a method to copy. A Clairol patent says a quaternary (conditioning-type) thickener gave "comparable and satisfactory" results, and separately that quaternaries and amines should be avoided "because of their known destructive effect on hair"; neither statement comes with numbers. On silicones in a bleach mix, we found no source at all.

Can you put purple shampoo or oil in bleach?

Purple shampoo: unproven either way. The route a maker describes is a separate toning step after the lightener is rinsed out: Olaplex's directions put toning after the post-lightener rinse. Purple shampoos don't share one dye: Acid Violet 43 is listed for some, such as Olaplex No.4P and Fanola No Yellow, while Lee Stafford uses Disperse Violet 1. The lab results on violet dye in bleach are few and point both ways (see "What the evidence can't tell you yet").

Oil. The only data we found are makers' patents about oils built into their own lightener formulas: Revlon got less lightening when it replaced its formula oils with water, and Henkel states, without data, that "Other care substances weaken the bleaching power". None of this tells you what coconut or any other retail oil does in a bowl.

Can you add Olaplex or another bond builder to bleach?

Usually yes, at the dose the bond builder's maker gives, added once the powder and developer are mixed, unless your lightener's own directions caution against it (BlondMe 9+, below) or you haven't checked them (see "Powders with bond technology built in"). Take the dose from the bond builder's own pack or mixing chart. What each maker says about developer and time differs, and Olaplex's own advice has changed:

• Olaplex, 2014–2015: lightening with Olaplex "takes longer to process"; "increase your level of developer one full level". A 2014 section said that at 40 vol "with Olaplex you are working with a 30vol. result", likening it to "diluting cranberry juice with water"; we found no data behind it. This is likely where the "Olaplex weakens developer" idea comes from; some retailer copy still repeats it. The 2015 FAQ also offered another fix: "Any issues with lift or processing time can be solved by using less Olaplex".
• Olaplex, September 2016: halved the No.1 dose and said "Do NOT increase developer", citing stylist feedback and cost per application, not test data. Stylists already bumping (going up a developer strength or adding time) "for tonal or time reasons" were told to continue.
• Olaplex now: its pro manual says to mix lightener and developer "according to manufacturer directions" and "Process as directed"; its UK product page says "No need to change your colour, lightener, or chemical service formulas". That lets you leave your formula alone; it doesn't forbid a bump.
• Wellaplex No1 (Wella): "No need to change peroxide or development time", though a footnote adds: "With lightening products the peroxide amount may vary."
• Fibreplex No.1 (Schwarzkopf): "Apply and process according to the instructions for use"; nothing on developer strength or time.
• Omniplex N.1 (FarmaVita): "no adjustment to the processing time or application time"; the sheet says nothing about developer.

None of these makers tells you to subtract developer to make room. The only subtract rule we found is Schwarzkopf's, for its own BlondMe Bleach & Tone additive. With BlondorPlex, taking a 6 ml foil dose of Wellaplex off the 45 g of developer Wella lists for 30 g of powder would leave about 1:1.3 (our arithmetic), below the 1:1.5 minimum Wella lists.

Powders with bond technology built in. Wella says BlondorPlex powder "already includes the active ingredient of WELLAPLEX No1"; the sheet doesn't forbid adding more. Schwarzkopf's BlondMe Premium Lightener 9+ page says: "Please note, the use of additional bonding systems may compromise performance", so follow the BlondMe directions as written. L'Oréal's Blond Studio 9 Bonder Inside page says "No extra mixing, no extra time!" and names nothing to add. We have not checked the directions for FarmaVita Omniplex bleach powders or Igora Vario Blond Plus with Fibreplex, so follow the pack.

What the evidence can't tell you yet

• No independent lift study. We found no independent study measuring lift with any bond builder in the bowl.
• Two company patents, both limited. These are tests a company runs to support its own patent, not peer-reviewed studies. A competitor's patent found about two-thirds of a level less lift with Wellaplex, on pre-dyed locks at 30 °C, with the dose unstated and no water comparison; the patent says the cause was "probably" dilution. That is less than one level, out of nearly seven levels the lightener lifted without it in that test (the patent converted lab lightness readings to levels by a method it doesn't disclose), and on artificially coloured locks it may not carry over to natural hair. A patent held by Hercules LLC (not Olaplex) found slightly less lift with Olaplex No.1 than with water, but at several times the 2016 label dose (our arithmetic), with 12% developer (twice the on-scalp ceiling above) and no repeat samples, so whether the gap is real is unresolved.
• Lab readings can mislead. In one study, hair treated with Olaplex No.0 a day after bleaching read lighter, so a lighter reading may not mean more lift.
• Violet dye in bleach. In Kao research (Nakamura, 2022), Acid Violet 43 broke down within 30 minutes in alkaline 3% peroxide, then dyed goat hair more weakly, though not to zero; that study didn't use persulfate. Two other violet dyes failed a patent stability screen in persulfate with 12% peroxide. In one 15-minute Milliken patent test, adding Acid Violet 43 to Fanola Violet Bleach Powder mixed with 40 vol reduced yellowness a little more than the same bleach with no added dye, and Milliken's purpose-made colourant more again. Purple shampoo itself wasn't tested in any of these.
• Bumping is unmeasured. We found no measurement of whether a stronger developer or longer time wins back lift, or what it costs in damage. If you bump, the makers' 20 vol on-scalp ceiling and maximum time still apply.
• Insurance. Two UK salon policy wordings we checked rely on products being used as the manufacturer instructs, and HABIA (the UK hair and beauty standards body) says UK policies typically do; "no data showing harm" doesn't mean you're covered. Both products' directions count: shampoo, conditioner or water in the bowl, or an extra bond builder in BlondMe 9+ against Schwarzkopf's caution, may fall outside the instructions those wordings rely on. We found no clause that deals with additives specifically, so check your own policy.

Questions people ask

How do you dilute bleach for hair?

Makers' directions don't dilute it with anything: they offer a lower developer from their own list and a powder-to-developer ratio inside their stated range. For a deliberately diluted mix, that is a bleach bath; see the bleach bath guide.

Can I add water to bleach to dilute it?

We found no lightener maker direction that includes it, and no measurement comparing a watered-down mix with an undiluted one. To make a mix milder, use a lower developer and a ratio inside the maker's range.

Can I put purple shampoo in bleach?

Unproven either way: we found no test of purple shampoo in a bleach bowl. The route a maker describes is a separate toning step after the lightener is rinsed out.

Can I mix conditioner with bleach to make it gentler?

We found no source showing it does. The makers' route to a milder mix is a lower developer from their list and a ratio inside their range; for a deliberately diluted mix, see the bleach bath guide.

Does adding shampoo make bleach work slower?

Nobody we found has measured it. No professional lightener directions we found include shampoo; to make a mix milder, use a lower developer and a ratio inside the maker's range, or see the bleach bath guide.

Does Olaplex weaken developer?

Olaplex said so itself in 2014 ("a 30vol. result") and dropped that advice in 2016 ("Do NOT increase developer"). The only lift data are two company patents with serious limits, so it isn't established either way. If lift is slow, Olaplex's own older advice was to use less Olaplex, and any bump has to stay within the lightener maker's 20 vol on-scalp ceiling and maximum time.

How much Olaplex goes in bleach?

Use your pack's mixing chart. Olaplex's 2016 bands were 1/8 oz (about 3.75 ml) per 30–60 g lightener for foils, or 1/16 oz (about 1.9 ml) under 30 g; about 1.9 ml per 30–60 g, or 1 ml under 30 g, on the scalp. We have no source confirming today's bands match.

Can you add Olaplex to BlondMe or BlondorPlex?

Schwarzkopf cautions that extra bonding systems "may compromise performance" with BlondMe 9+; Wella says BlondorPlex already contains Wellaplex No1's active. Neither names Olaplex.