What Is Wheat Protein, What Does It Do? Hydrolyzed Wheat Protein
Other names: Hydrolyzed Wheat Protein, Hydrolyzed Wheat Gluten
Wheat protein is the broken-down form of protein obtained from wheat; it appears on labels as Hydrolyzed Wheat Protein. In hair it attaches to the strand, small peptides can move into the strand and slow water loss, but it does not repair the strand. People with a wheat allergy should be careful: in Japan, a facial soap containing this kind of protein led to thousands of allergy cases.
See products for youAt a glance
- INCI names
- Hydrolyzed Wheat Protein, Hydrolyzed Wheat Gluten
- Source
- Wheat gluten, broken down with acid or enzyme
- What it does
- Attaches to the strand, gives slipperiness, may slow water loss
- Safety criterion
- An average molecular weight of 3.500 Daltons or less is recommended
- Caution
- People with a wheat allergy should consult an allergist before use
What's on this page?
Wheat protein used in hair care is obtained by breaking the gluten in wheat into small pieces with acid or enzyme. This process makes the protein water-soluble, so it can be added to a shampoo, cream or spray. It is used as a plant-based alternative to animal proteins such as keratin, but, as one review notes, it does not replace damaged keratin. Its effect on hair has been studied quite well in the lab, while its allergy side has come to attention through a serious incident.
How does it work on hair?
The size of the pieces used determines the result. In a study with peptides averaging about 1.000 Daltons, pieces marked with a fluorescent dye were seen to penetrate the hair extensively. On split ends, the dye spread across the whole cross-section.
| Finding | How was it observed? | Its limit |
|---|---|---|
| Peptides enter the strand | By confocal microscopy, in hair samples | Laboratory condition, not at product level |
| Water loss slows | In protein-treated strands, recovery of the stretch response took hours | The rate of drying changed, not the moisture amount |
| Better adherence to the strand | With chemically modified wheat protein | A new product trial, single study |
| Against heat | Tested in a 1% solution | No strong data for this purpose |
The third row in the table has a rationale. In the same study's peptides, acidic amino acids made up a high share, around 36%, while positively charged lysine was below 1,5%. Since the hair surface is also negatively charged, this structure is not advantageous for electrical attraction. For this reason, positively charged derivatives with names containing Hydroxypropyltrimonium or similar were developed.
The authors anticipate that this water-retaining property could help against split ends, but this remains a prediction. In hair care, wheat protein is a retained care substance, like keratin. Whether a few minutes of contact achieves the extensive penetration seen in the experiment has not been measured. It does not rebuild broken bonds, and its effect fades with washing. In leave-in products such as blow-dry spray it stays on the hair longer; you can see the formulas of these products on the blow-dry spray page.
Wheat allergy note: The soap incident in Japan
The event that makes this ingredient notable happened in Japan. Allergy reports began in the early 2010s among people using a facial soap containing hydrolyzed wheat protein. A nationwide screening confirmed more than 2.000 cases. In some, there was itching and hives on the face and eyelids; in others, exercise-triggered anaphylaxis after eating wheat foods was seen.
What is striking is that these people had no prior wheat allergy. Sensitisation is thought to have developed through skin and eye contact during soap use. The protein in the soap had been treated with acid and was a relatively long-chain product. The safety assessment after this incident reached this conclusion:
- Hydrolyzed wheat protein and gluten are considered safe in cosmetics when the average molecular weight of the peptides is kept at 3.500 Daltons or below.
- No allergic sensitisation or immediate reaction is expected when the polypeptide length does not exceed 30 amino acids.
The problem is that the label does not state molecular weight. So what you can do as a user is pay attention to the ingredients and recognise symptoms:
- If you have a known wheat allergy: When you see these names on a label, consult an allergist before use.
- If itching or hives appear on the face or around the eyes while using it: Stop the product and see a doctor. Take this symptom seriously, because a reaction to wheat foods may develop later.
- If breathlessness, throat swelling or a feeling of fainting occurs: Call emergency help.
- If you are going to try a new product: First try it on the inner arm or elbow crease, twice a day, for 7-10 days.
What is known for coeliac patients?
Coeliac disease is triggered by gluten taken orally and is a different condition from allergy. There is no data showing that gluten applied to healthy skin starts this process, so for coeliac patients the main concern is not swallowing the product. Still, there is no large study examining this in coeliac patients. Make sure the hair product does not reach the mouth, wounds or cuts; if unsure, ask your doctor. Products applied to the lips need a separate assessment.
How does it appear on the label?
Most often it appears as Hydrolyzed Wheat Protein or Hydrolyzed Wheat Gluten. Chemically modified derivatives meant to attach better to the strand also carry the words Wheat Protein in their name. You can read how protein products should be assessed for hair on the hair protein care page.
This page is for general information only and does not replace medical diagnosis or treatment. If you have an ongoing skin or scalp problem, consult a dermatologist.
