Eyebrows serve two main functions: first, communication through facial expression, and second, prevention of sweat, water, and other debris from falling down into the eye socket.
As with any hair in the body, brow hairs have a growth cycle – it sheds and grows back. Brows usually have a life cycle of 100-150 days. Typically 3 to 5 hairs are shed per day, depending on genetics, health and environmental factors. It takes approximately 4-16 weeks for a hairs to complete an entire growth cycle. If they are pulled out prematurely, they usually grow back in 90 days - given that there is no damage to the hair follicle.
There are three different growth phases in the life cycle: anagen, catagen and telogen.
Phase 1: Anagen (Growth) Phase - 30 to 45 Days
The anagen phase is when the hairs are actively growing. Each hair has a daily growth rate of 0.12mm to 0.14mm, and will usually reach a maximum length of 12mm by the end of this phase (30 to 45 days).
Phase 2: Catagen (Transition) Phase – 14 to 21 Days
The catagen phase is when the hairs stop growing, and the hair follicle shrinks. It takes approximately 14 to 21 days for this phase to complete. If a hair is pulled out during this phase, it will not grow back immediately as the follicle needs to complete the catagen phase.
Phase 3: Telogen (Resting) Phase – 100+ Days
The Telogen Phase is when the full-grown hairs are resting - this can last more than 100 days before the hair falls out and triggers the growth cycle to begin again.
At any point in time, clients will have hair in every phase of the growth cycle. As such, it is normal for clients to naturally shed 2-5 hairs daily. This is important to understand since the growth cycle is the reason why brow laminations only last up to 6-8 weeks. Hairs grow, shed, and eventually a new hairs will replace the old one.
Brow lamination only changes the shape of the hair that Is processed – it does not change the shape of the hair that grows out. The brows may a bit unruly towards the 4 week mark as it grows out. The faster the natural hairs grow, the sooner the brow lamination will grow out. To maintain the sleek laminated appearance, we recommend using proper aftercare, proper styling products and scheduling a re-lamination appointment every 6-8 weeks.
BIOLOGICAL FACTORS THAT AFFECT THE GROWTH CYCLE
Medications are designed to treat various health conditions, but may have side effects that can disrupt the natural growth and composition of hair. The severity of side effects depends on the type of drug, dosage, and time they've been on it.
Depending on the medication, it can contribute to excess hair loss. There are two types of hair loss caused by disruption of the growth cycle: anagen effluvium and telogen effluvium. Anagen Effluvium hair loss is caused by a disruption in the growing phase and hair follicle damage - this usually occurs in those undergoing chemotherapy or radiation. As 80-90% of lashes are in the anagen phase, a large number of lashes and follicles are affected. Telogen Effluvium hair loss is caused by the shortening of the growth cycle. The hair follicles enter the telogen phase too soon and cause the lashes to shed prematurely. Those with this condition will usually shed 30-70% more than normal.
Common Medication with Hair Loss as a Side Effect
- Acne medications containing vitamin A (retinoids)
- Antibiotics and anti-fungal drugs
- Birth control pills
- Anti-clotting drugs
- Cholesterol-lowering drugs
- Drugs that suppress the immune system
- Drugs that treat breast cancer and other cancers
- Epilepsy drugs (anticonvulsants)
- High blood pressure medications (anti-hypertensives), such as beta-blockers, ACE inhibitors, and diuretics
- Hormone replacement therapy
- Mood stabilizers
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Parkinson's disease drugs
- Tamoxifen blocks the estrogen receptor to prevent breast cancer.
- Thyroid medications
- Weight loss drugs
Clients who are on medication are still suitable for a brow lamination, given that there are no other contraindications that would deem it unsafe to do so. Medication affects everyone differently, so not everyone will experience hair loss. Regardless, it is important to discuss the possibility of the medication affecting their results.
MEDICATIONS AFFECTING THE GROWTH CYCLE
Natural hair growth is regulated by hormones – androgens, estrogens, thyroid and parathyroid hormones, prolactin, corticosteroids, somatotropin and melatonin.
The most crucial hormone contributing to hair growth is the thyroid hormone, as it ensures the proper metabolism of proteins, fats, carbohydrates, vitamins and minerals. Once metabolized, these nutrients are delivered to different organs. High levels of thyroid hormones causes lashes to grow faster. Low levels of thyroid hormones causes lashes to grow slower. Changes in the environment will change the thyroid hormone levels in the body. The body has the lowest thyroid hormone level in the winter, medium level in summer and autumn and the highest in the spring. As a result, hair grows the slowest in the winter and fastest in the spring.
Adrenaline is a hormone that is naturally produced by the body. During high-stress periods, the body produces an excess amount of adrenaline which gets converted into cholesterol. The raised levels of cholesterol results in increased levels of testosterone. In women, a raised level of testosterone can affect the hair growth cycle by prematurely causing the hairs to enter the telogen phase, which results in hair loss.
Vitamin A, B, C, D and E are vital for hair growth. Vitamin A helps cells grow and help skin glands produce sebum to keep hair moisturized and healthy. Vitamin B is essential for keeping hair follicles oxygenated and helps deliver nutrients to the hair follicles for growth. Vitamin C prevents damage from free radicals and hair from aging. It also aids in iron absorption, which is essential for hair growth. Vitamin D is linked to the production of new hair follicles, which leads to increased hair density. Vitamin E prevents oxidative stress and promotes hair growth.
There are so many changes that happen as the body ages, affecting the hair growth cycle and health of the hair. It is entirely normal for hair to start thinning as we age. The hair growth cycle can slow down or completely stop due to a drop in certain hormones. The skin surrounding the hair become drier, which prevents the hair from retaining moisture and therefore causes them to become brittle and break.
Age also has a huge effect on the strength and growth cycle of lashes, due to change in hormonal and protein levels. Hairs get weaker and thinner with age as hormone levels and building blocks for hair growth decreases. Older clientele should be laminated with caution, as the natural hairs are weaker. Lifting weak brow hairs can damage the hairs.
Pregnancy, Postpartum and Menopause
These are the three most significant hormonal shifts women will go through, which will affect the hair growth cycle. These hormonal shifts are phases, meaning that the disruption in the growth cycle is usually temporary. Typically, the hair growth cycle will return to normal once the body's hormones are balanced again.
Pregnancy causes a surge of hormones going through the body that affects the growth and texture of the hair. Some women notice quicker growth and shinier hair by week 20 of pregnancy. A brow lamination will grow out quicker due to the growth cycle speeding up. In other cases, hair can also become drier and more brittle, resulting in them breaking. The hair can also become resistant from lifting due to hormonal changes. We do not recommend serving those who are pregnant as the brow laminations come into contact with the skin and can potentially by absorbed by the body. Should a reaction occur, it is very difficult to treat.
Postpartum lash loss (and hair loss) is due to the drop in estrogen levels after giving birth. The decline in estrogen causes the hair to grow slowly and triggers the increase in the production of androgens which causes the hair to fall out. The most significant loss usually occurs within 4 to 5 months after giving birth and typically slows down after three months.
Menopause is the time that marks the end of the menstrual cycle. It can happen anywhere between the age of 40 to 58. Hair loss is caused by the drop in estrogen and progesterone, and the increase in the production of androgens.
Hormonal shifts are different for everyone, so it's impossible to predict whether a client will have good or bad results. It's important to discuss with your client to ensure that they're aware of the results.