Efficacy testing: hair growth & anti-hair loss
Eyelash lengthening, volumizing, curling, growth-stimulating.
General hair testing protocol
Number of subjects
20 (determined by client)
Place of application
Scalp / Hair
Testing time
4 weeks (determined by client)
Sample requirement
Equal to the number of subjects
Measurement points
- T0 – before application
- Tx – after x weeks (determined by client)
Procedure
- First measurement on the testing site (“BEFORE testing”)
- Product used by participants at home during the testing period
- Repeated last measurement on the testing site (“AFTER testing”)
Signs of hair loss.
Signs of hair loss.
Many factors can affect hair growth rate, such as mechanical stress (pulling or stretching of the hair), pressure on the scalp, certain externally applied substances, heat etc. Furthermore, hair loss and baldness can manifest as a result of hormonal changes, dietary deficiencies, exposure to toxic substances, infections or other diseases.
However, the most common cause of baldness is hereditary hair loss that appears with age. Hair loss can come suddenly or gradually and can affect the scalp or the entire body. It may be temporary or permanent.
Claims related to hair care
- Hair density increase
- Hair growth
- Anti-hair loss
Measurement principles and instruments.
Measurement principles and instruments.
To prove hair related claims, we measure the following parameters using the following instruments:
Evaluation of hair growth with the microcamera
- Soft FX (Callegari, 1930)
See our results.
Microcamera Soft FX (Callegari, 1930)
Hair structure and growth.
Hair structure and growth.
The elongated part of the hair that extends above the surface of the skin is called the hair shaft. It grows from an elongated tube-like structure in the skin called thehair follicle.
A hair follicle is lined by epithelial cells and is often associated with one or moresebaceous glands, which secrete sebum into the follicle, and an arrector pili muscle, whose contraction can cause the hair to stand upright. At the base of the follicle is the dermal papilla, a connective tissue structure containing blood vessels and signaling cells that help nourish and regulate the growing hair follicle.
The main structural component of hair is the protein keratin. The hair shaft consists of many thin keratin fibres arranged into thicker bundles. It is generally made up of three layers. The innermost region is the medulla, which may be absent or discontinuous along the length of the hair. Its presence can influence some optical properties of hair, although hair colour is mainly determined by melanin in the cortex. The middle and largest layer is the cortex, which provides much of the hair's strength, elasticity, and colour. It is composed of keratinized cells that were formed in the hair bulb and became hardened and dead as they moved upward during hair growth. The outermost layer is the cuticle, a thin protective layer that surrounds the hair shaft and helps protect the cortex. The cuticle surface is covered by a hydrophobic lipid layer that includes 18-methyleicosanoic acid (18-MEA).
Hair fibres can be characterized by colour, shaft shape, such as curly, straight, or wavy, and microscopic features. Keratin microfibrils in the cortex contribute to the mechanical properties of hair, while optical and surface properties are strongly influenced by the cuticle, particularly the condition of the 18-MEA-containing surface layer.
The life cycle of a hair includes three stages. The first stage is the active growing phase (anagen), which is characterized by repeated division of hair cells and steady hair growth. The next phase is the transition phase (catagen), which is a relatively brief phase, during which the hair stops growing. This phase is followed by the resting phase (telogen) when the replication of the hair cells at the base of the hair follicle stops and so does the hair growth. By the end of this phase, the hair can be easily pulled from the scalp. After this phase, the new hair appears from the same follicle during the beginning of the next cycle of hair growth and pushes the old one out.
A protocol built for your claims.
Efficacy testing protocol is prepared for each product individually with close cooperation with the sponsor. Based on the claims, usage regime and efficacy expectations, we prepare a protocol that is suitable for the type of product and can confirm product efficacy. The studies can be performed over a different time period (from a few days to several weeks or months) depending on the claim and type of measurement.
Ready to prove your hair growth claims?
Speak with our experts about a tailored efficacy testing protocol for your cosmetic product.
