Yay, Science! Okay, here's what I could find about the ingredients in the Shampoo:
Sodium Cocoyl Glutamate is a mild, non-irritating, all natural, plant based surfactant. So you should be okay there.
"Decyl Glucoside is a, natural, non-ionic surfactant, ideal for all foaming and cleansing products. Our Decyl Glucoside, obtained from renewable raw materials, is a combination of plant based fatty alcohols (coconut c8-16) and glucose (corn starch). Decyl Glucoside is a mild surfactant and because it does not dry it is ideal for the formulation of personal hygiene and toiletry cosmetics. " (From: Ingredients to Die For
"BabyFoam (SCI), also referred to as Sodium Cocoyl Isethionate, is an, extremely, gentle surfactant based on coconut fatty acids. Mild enough for baby cleansers, personal hygiene and toiletries while still offering very efficient cleansing and low odor.
BabyFoam (SCI) is a very pure surfactant, with a high active surfactant level of 84%, making it an economical choice because the usage rate is lower then blended surfactants. BabyFoam (SCI), Sodium Cocoyl Isethionate, delivers excellent, luxurious, foam while, leaving a very nice silky feeling on the skin. Sodium Cocoyl Isethionate does not dry the skin, or the hair, making it an excellent choice for the formulation of all cleansers (surfactant). One of the most popular choices for shampoo / body bars due to its, high, performance in soft or hard water. " (Same source)
Cetearyl Glucoside: Formed by combining fatty alcohols with glucose. "
An emulsifier used in oil in water formulations. It helps skin and hair retain moisture, and gives a velvety after touch." (From: Truth in Aging
"Methyl Gluceth-20 is a water soluble emollient and humectant produced from Glucose and Methyl Alcohol and originally derived from corn sugar and corn starch. It is a versatile, gentle, effective humectant, emollient, and foaming agent that imparts a smooth feel to the skin. Methyl Gluceth-20 is specifically used for its moisture retentive qualities and ability to open pores and follicles" (Same source)
^^ Check into this one. It could be the humectant that's making trouble. How is your hair with other humectants?
Then you've got a bunch of oils, and then another humectant:
"Sodium PCA is a naturally occurring humectant found in human skin that is a derivative of amino acids. Sodium PCA has high water absorbing properties, and is also considered to be hygroscopic, with the ability to absorb moisture from the air (VitaminStuff.com and other research). It can also bind moisture to cells, and hold several times its weight in water. It delivers moisture to the hair and skin, and is often seen as an emollient or humectant in hair conditioners and moisturizers; it is also seen as an ingredient in shampoos, hair sprays, permanent waves, skin fresheners and other hair and skin care products, according to RealSelf.com." (same source)
This is all I could find on the Panthenol B5:
"Provitamin B5 (synonyms: D-pantothenyl alcohol, pantothenol, dexpanthenol) is the alcohol analog of pantothenic acid (vitamin B5). Activity 75%. pH 8-9
. ... Soluble in water and alcohol, not in oils. ... Properties: Penetrates readily skin and hair, potent moisturizer and softener of the skin, makes the skin more elastic, soothes irritated skin (anti-inflammatory effects), heals minor wounds (promotes epithelialization), gives the hair moisturisation and shine, reduces spilt ends." (amazon.ca description)
Human hair is usually pH 5, and this one has a much higher pH. That could also be causing the issue? For more information on pH and hair:
How pH relates to hair
pH and curly hair
And all I could find on Glycereth-2 Cocoate:
(from kao chemicals
Benzoic Acid is a preservative.
So. All I can tell you is to learn about pH and how the pH of a product interacts with your hair. I can't help you a ton here, because I'm still learning! I can also tell you that my hair ALWAYS did better with shampoos that had very few surfactants. Then I moved to co-washing and haven't looked back!!