Monday, January 27, 2014

Deep Conditioning, Part I

Note: This series applies to Protein Deep Treatments too!

This is the first of a two part post. Today's post is about how deep conditioners work and who needs one. Part two is about how to use a deep conditioner to get the most out of it.

Deep conditioning on wet hair is applying conditioner to freshly washed hair to leave on for a few minutes (or longer). You could put a deep conditioning treatment on unwashed hair, but because you'll get the best result from having the conditioning treatment in complete, unfettered contact with your hairs. It's better to deep condition clean hair and get rid of the dust and dirt and pet hair, twigs, leaves and other junk first.
©Science-y Hair Blog 2014
A pH level of 7 (or at least around 7 and above 5) has been shown in laboratory testing to promote the most adherence of conditioner to your hair. It is best to stay between pH 6 and 7.  Most store-bought conditioners will already be in this range. If you start adding acidic or alkaline ingredients, get some pH test strips and test the pH of what you're adding. If you want to maximize your hair's uptake of conditioner, you want control of the pH.©Science-y Hair Blog 2014

Normally (non-wet) hair has a net negative charge - more negative charges than positive charges. Especially normal porosity and porous hair. For most of us, hair below ear or chin length is normal porosity. If you color or highlight your hair, brush it often, spend a lot of time in the sun or swimming pools, or it is very long, the ends are likely to be porous.©Science-y Hair Blog 2014

The more porous the hair, the more easily dehydrated it is. And the more negative charges it has. Porous hair also has gaps in the cuticle "covering" that are temporarily patched in by this adhering of conditioner to negatively charged surfaces.
©Science-y Hair Blog 2014
Dry (not wet) hair has more negative charges 
thanpositive charges.
What's the deal with negative charges?
Conditioning ingredients have positive charges that allow them to interact with negatively charged hair. Like magnets, positive is attracted to negative. The conditioning ingredients adhere (technically accurate term: adsorb) to your hair temporarily and do not rinse off. This leaves a layer of conditioning behind to help reduce friction in your hair and add softness and flexibility.©Science-y Hair Blog 2014

What sorts of ingredients have positive charges?
Hydrolyzed proteins - slightly positively charged
Stearamidopropyl Dimethylamine
Behentrimonium Methosulfate
Behentrimonium Chloride
Dicetyldimonium Chloride
Distearyldimonium Chloride
Polyquaternium 55
Guar Hydroxypropyltrimonium Chloride 
Cetrimonium Bromide
Cetrimonium Chloride
Palmitamidopropyltrimonium Chloride
Laurdimonium hydroxypropyl hydrolyzed wheat or soy or keratin protein
Cationic conditioner (pink + symbols) adhering (adsorbing) to the negative charges on hair at
the proper pH at left. Conditioner not adhering to hair at a too-low pH at right.

But wait! There's more to conditioning than positive and negative charges: When lipids (oily ingredients) are present in a conditioner formula (or when you add them), you get even more conditioning goodness adhering to your hair - more cationic conditioning and more softness and flexibility from the lipid. It's an interesting mutual enhancement of conditioning ingredients for an even better end result. The presence of lipids in a formula makes it a better deep conditioner. Lipids themselves are great hair softeners and lubricants.
©Science-y Hair Blog 2014
In most conditioners, the lipid is already present in the form of cetyl alcohol or cetaryl alcohol because this ingredient makes a nice creamy, thick conditioner with a soft after-feel. But other oils do the trick also, including plant oils or butters you might add to a conditioner. Adding extra oil to a conditioner really does turn it into a deep conditioner! Sounds like a money-saving tip to me. 

What else is good in a deep conditioner?
If you have porous hair - hair that always seems to soak up oil and conditioner, your hair will probably appreciate hair-penetrating oils in a deep conditioning treatment; coconut oil, sunflower oil, possibly grapeseed oil to help your hair avoid excessive swelling in water. Cetrimonium bromide and probably Cetrimonium chloride can penetrate the hair shaft slightly for a "deeper" conditioning effect, and so can panthenol and amino acids from hydrolyzed proteins.

If you have tangle-prone hair or tightly curled or coiled hair, just about any oil is a good addition because you need lots of lubrication to keep your hairs sliding past each other. Butters like shea butter can be good in some people's hair and cause build up or friction in other people's hair. Warm them so they melt and mix them thoroughly into your other ingredients.

Almost any hair can benefit from moisture-hugging humectants - warmed honey, aloe vera, glycerin (maybe, it works better in humid weather), look for Hydroxypropyltrimonium honey, Sodium PCA, panthenol, Hyaluronic acid.©Science-y Hair Blog 2014

Proteins: If your hair handles protein well (see this post about protein), it can be a good ingredient in or addition to a deep treatment. Hydrolyzed protein helps your hair stay hydrated. Protein in products slows moisture loss from your hair. Look for products containing hydrolyzed proteins, amino acids and peptides. Proteins carry a weak cationic charge, so they play by the same rules for heat and length of time that are coming in Part II.  

Salt? When salt is added to conditioner, it decreases adsorption (ahderance) of conditioner to hair. Instead of conditioner adsorbing to your hair, the salt does instead because it has more "charge." The salt blocks the conditioner. Salt may feel slippery and humectant-y once in a great while, but if used often it creates friction in hair. Salt attracts water strongly (creates an osmotic gradient and will pull water to itself from anything else that has water). If salt is in your water-based conditioner on wet hair, there's plenty of water for the salt. But left on your hair, the salt molecules will pull water from your hair. That's how it can act as a humectant in humid air, but in dry air - that salt will pull water right out of your hair. Have you ever salted eggplant to pull out the water before cooking it? Or salted cucumbers or cabbage before making pickles or sauerkraut? Salt pulls water to itself. Better not salt your hair too often.

Whose hair needs deep conditioning? Not everybody's. Lower porosity, un-bleached or un-dyed hair cannot adsorb much conditioner and it's more likely to accumulate build-up. 

I don't lump hair into categories readily because everybody's hair is so much alike - and so different! I think about hair at the microscopic level, at the "individual hair strand" level, and also about the forces acting on hair like whether it is straight or curly or kinking because force on hair is distributed very differently on and within tightly curled hair relative to more loosely curled or straight hair. 
©Science-y Hair Blog 2014
So whose hair needs deep conditioning?
  • Bleached hair (highlights, "lightener," hair dyed with permanent-color or demi-permanent color)
  • Very long hair that feels dry and rough on the ends
  • Hair that tangles easily (it may be straight, wavy, curly or tightly coiled)
  • Hair that is experiencing a lot of breakage (at the ends, mid-shaft splits, or anywhere else)
  • Hair that is acting frizzy or poofy or flyaway and needs weight and/or slip to pull itself together
  • Hair that feels constantly dry
  • Hair that has spent many hours in the full summer sun, in swimming pools, in salt water, in dry wind
  • Hair that feels dry, rough, inflexible and dull
  • Hair frequently straightened or curled with high-heat styling tools (high heat blow dryer, curling iron or straightening irons)
  • Hair that has been chemically straightened or curled

In Part II: How to use a deep conditioner to get the most benefit, how to deep condition low porosity hair - and more.

Journal of Cosmetic Science Vol. 4 No. 3, 259-273 September/October 1992
Assessment of the substantivity of cationic quaternary compounds to hair by potentiometric titration using the surfactant electrode. NGHI VAN NGUYEN, DAVID W. CANNELL, ROGER A. MATHEWS, and HANS H. Y. OEI

Journal of the Society of Cosmetic Chemistry Vol. 4 No. 5, p. 85-94 1994
Adsorption to keratin surfaces A: continuum between a charge-driven and a hydrophobically driven process.

Journal of Cosmetic Science, 60, 85–95 March/April 2009
The effects of lipid penetration and removal from subsurface microcavities and cracks at the human cuticle sheath


Chemical and Physical Behavior of Human Hair 
Robbins, 1994. 3rd Ed. Springer-Verlag, New York


  1. First post disappeared :( Here's the short version:

    mid back length, frizzy, dry, porous, and daily breakage despite CO most days and no heat (besides living in TX)

    Are the salts in body sweat an overlooked hair issue? I'm a fitness instructor and sweat a lot several times a week.

    If so, what are your recommendations for compensating?

    Henna. I use high quality brand 2x a month for coloring roots. I use apple juice as a gentle dye release base. Is Henna a good protein treatment? any cons for porous hair?

    I'll keep reading! I know i must be doing something wrong lol

    1. Hello Ricki,
      Salt in body sweat is an overlooked issue in hair chemistry as far as I know. But when you exercise often, your body conserves salt and your sweat gets less salty. The same thing happens when we move from cooler seasons to warmer seasons - our sweat gets less salty as we sweat more to avoid losing necessary electrolytes.

      Henna is not a protein treatment. Henna coats the hair. Not so much that it obscures the details and not even so much that it changes the porosity. But like conditioners and like proteins, it does coat the hair. In doing that, henna tends to create friction like proteins sometimes do. Hennaed hair often needs plenty of lubrication (slip) - enough conditioner to help any tangles slip right out.

      If you are having dry, porous hair and breakage and you're using plenty of conditioner (or coconut oil if CO stands coconut oil) then your hair is asking for a different approach.

      Your hair may need some protein in rinse-out or leave-on products or as a protein treatment to help your hair behave as though it is not porous. You may need to do oil pre-wash treatments with sunflower oil or avocado oil or olive oil and leave it on for 6-8 hours so the oil can "soak in" and protect your hair from swelling during washing. If coconut oil works, use that - but it makes some hair more brittle. You don't have to soak your hair in oil - start with just a little.
      Use the search feature of the blog (and the popular posts at right) for more info. on all these things.
      Good luck!

    2. Where have I been? I have been natural for years, unfortunately, my hair is coarse, dry, and grey, also damage from me not knowing how to care for it. I complained so much till someone told me about this blog. I absolutely love it and wished I could have found you along time ago. Such informative information, I so up every night just going through your blog trying to learn and get more knowledgeable of my hair. Hoping to get it in shape. As I said, my hair is damage fr lack of care. But I went out and bought the shampoo, conditioner, and deep conditioner for my type hair. I don't know if I am protein sensitive b/c when I did protein treatments before I never did a moisturizing conditioner afterwards. My hair has no elasticity? Can you help me with that? I read somewhere the more elasticity you have in your hair the healthier it is.
      Thank you so much

    3. Again I forgot to mention, I have a water softener. And it uses salt, could that be one of my culprits that is causing dryness to my hair?
      Thank you so much

    4. Hello Karen Anderson - On the "popular posts" link at the right side of the blog is a link to the post, "Managing elasticity and porosity in your hair." That might be a good place to start. -W

  2. Clear article about deep-conditioning :)

    So salts should be avoided in regular leave-ins. But is a salt (e.g. magnesium and sodium chloride) still drying if it's somewhere lower on the ingredient list? And how to take extra measures as porous/kinking curly if you use Yes To Carrots Pampering Co as LI since it contains sea salt?

  3. Sera,
    The sea salt is less likely to be a problem in Yes To Carrots Pampering Co because of all the emollients and conditioning ingredients in the product. It's confusing too, the mention of "maria aqua" could be mineral water - adding sea water to conditioner would not make sense so it's uncertain if there is salt in the product at all (to me).

    Recipes I have seen for adding salt are usually in high concentrations - 1 tablespoon salt to a cup of conditioner, or equal parts salt and conditioner (or some variation - lots of salt) and this is far, far more salt than in Yes To Carrots Conditioner.
    If you notice negative effects using this as a leave-in, you may need to use it only as a rinse-out conditioner.

    1. Thanks for your thoughts about YTC :).

      Today I saw a CG-friendly conditioner in the drugstore that contains a.o. shea butter, almond oil/extract and glycerin in the ingredients list (but I don't know yet which type of -monium Chloride).

      Since you wrote that shea butter may cause friction/tangles when used as pure butter, does this butter then work differently when included in a conditioner formulation?

    2. I have heard some people who have trouble with pure shea butter also have a problem with shea butter included in a conditioner formula. And I know that some hair can't tolerate products containing shea butter. On the other hand, some people's hair benefits greatly from a little friction in terms of curl definition or maintaining volume. If pure shea butter causes friction or tangling or a waxy feel or dullness in the hair and one is using very small amounts, then it seems reasonable to avoid shea butter in a conditioner formula as well. But if small amounts of pure shea butter are not a problem, it may be just fine in a conditioner. I think if a person does not know their hair's response to shea butter, it's not necessary to avoid shea in products. But when using shea butter -containing products, it is helpful to know that dullness, wavy feeling, increased tangling can indicate that shea butter is a "problem ingredient."

  4. Phones acting a bit weird, so my apologies if this is a multiple entry!

    I'm hoping you can help me out! My hair had been feeling really dry from the colder weather, so I applied coconut oil from mid-length to ends of my hair, then shampooed as usual and conditioned. I used TONS of conditioner to make sure very strand was soaked. At first, my hair seemed to have more of a wave, but by the afternoon, it just felt so dry and my split ends have come out in full force! I definitely don't feel any residual coconut oil. Is it possible I over condition? I was also wondering if the coconut oil just seals any current moisture, so if you don't have any, you're just sealing nothing? I think I have fine/medium hair that's very porous, but am currently collecting my strands for an analysis :). Anyways, I'm thinking about just using a deep cleanser tonight to strip whatever I've got right now and just shampoo/condition as usual. Good or bad idea?

    Thank you!!

    1. Marie,
      It sounds to me from your description like your hair did not react well to the coconut oil. Coconut oil can make some people's hair feel stiff or dry or brittle or hard. In that case, it might be better to use a different oil such as sunflower oil, avocado oil or olive oil. Those should not give you the same reaction as the coconut oil did.
      If your hair can handle a deep cleansing without any bad effects, it might help "re-set" your hair to how it was before the coconut oil. Give it time too - sometimes it takes more than one "wash cycle" to get over something like that.

      Oils used for a deep-conditioning treatment on dry hair don't necessarily seal moisture in so much as they soften and lubricate hair and (if they are hair-penetrating oils at all) help protect the hair from dehydration that tends to occur when hair gets wet. Oil for sealing is a step in the styling process.

      Trying different oils is worthwhile because you'll probably find one you really like and you can cook with the rest. Different oils are truly different products and some hair can be very picky about which oil(s) it likes best.
      Good luck!

  5. Thank you for your informative articles. I recently discovered both my & I hair has been damaged & the culprit was our hard water. Our hair porosity & now it is high. I just cut over eight inches of hair because I was frustrated with my hair breaking like crazy & gets dry very easily. Is there a way for our hair to get back to normal porosity without cutting anymore of my hair off because my husband does not like my hair short. I also have been using distilled water to wash my hair since the damage.

    1. Hello D,
      Have you tried any deep conditioning? If deep conditioning does not work, sometimes using oil treatments before washing does work and there is a post linked on the right of the page about using oil treatments. If your hair is not coarse (wide hairs), then hydrolyzed protein might work well to stop the breakage. You can use deep conditioning, protein or oil treatments every 1-2 weeks if your hair responds well to any of those.

      In the Unites States, there is a product called "Watersticks" which makes a water softener that is just for showers - not the whole house. It is not inexpensive ($200) and needs to be recharged weekly, but in the long run, that might cost less than washing your hair in distilled water. It also has a filter which removes chlorine, which is helpful if you use treated "city water" and are not using a well. Good luck!

  6. Someone suggested that I use salt mixed with conditioner to fix my protein overload. Is this correct? If not, what is the best way to correct this issue?

    1. Hello Carmiebear,
      There is a section about salt in this very post. Salt will interfere with the way conditioner usually bonds to hair. But it can also add a very slippery feel to that conditioner. I don't know whether salt has the ability to "knock off" proteins that have bonded to damaged areas, that might be possible if the negative charge on the salt were able to attract any positive charge on proteins.
      If protein has left your hair feeling stiff or dry or too soft and flat - obviously you'd want to avoid protein for a while. Use oils that get along well with your hair, deep condition if your hair responds well to that.
      If stiffness is what protein overload feels like - oils and conditioners provide the opposing effect - softness. So that's the direction to go. Good luck! -W

  7. Quick question: could any of your diys help combat STATIC & hardcore flyaways?
    Many thanks!

  8. your Hair conditioner article was nice and informative