FUNCTION
Eyelashes have a particular and essential function – they prevent foreign matter from getting into the eyes. Specifically, lashes protect the eye pupil; therefore, the lashes are always longer and denser in the center of the eye and become sparser in the inner/outer corners. Each eyelash has nerve sensors that cause the eyelid to instantly close when foreign matter, such as dust, hits it - this filters out foreign matter and protects your eyes
LAYERS
Natural lashes are composed of 2-3 layers of vertical layers. The number of layers is influenced by genetics and health.
The outer and inner corner of the eye usually has 1-2 vertical layers, and the middle usually has 2-3 vertical layers. More vertical layers are in the middle to prevent foreign matter from entering the eyes.
On average, there are 90-150 lashes on the upper eyelid and 70-80 lashes on the bottom lash line. The number of lashes an individual has is dependent on genetics and health.
DIRECTION AND SHAPE

Natural lashes can point downwards, straight or upwards and have a straight or curly curvature. Genetics is partly responsible for the shape of the hair follicle; however, hormones, drugs and chemical treatments can potentially change the shape of the follicle, which means that the natural lash direction and shape can change over time
GROWTH CYCLE

As with any hair in the body, lashes have a growth cycle – it sheds and grows back. Lashes usually have a life cycle of 100-150 days. Typically 3 to 5 natural lashes are shed per day, depending on genetics, health and environmental factors. It takes approximately 4-16 weeks for a lash 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 – Baby Lashes – 30 to 45 Days
The anagen phase is when the lashes are actively growing - approximately 40% of the upper lash line and 15% of the lower lash line are in this phase. Each lash 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 – Teenager Lashes – 14 to 21 Days
The catagen phase is when the lashes stop growing, and the hair follicle shrinks. It takes approximately 14 to 21 days for this phase to complete. If an eyelash falls out or 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 – Adult Lashes – 100+ Days
The Telogen Phase is when the full-grown lashes is resting - this can last more than 100 days before the lash falls out and triggers the growth cycle to begin again.
At any point in time, clients will have eyelashes in every phase of the lash cycle. As such, it is normal for clients to naturally shed 2-5 eyelashes daily. This is important to understand since the lash cycle is the reason why lash lifts only last up to 6-8 weeks. Eyelashes grow, shed, and eventually a new eyelash will replace the old one.
Lash Lifts only change the shape of the hair that Is processed – it does not change the shape of the hair that grows out. The lashes may appear wonky or kinked at the tip when it grows out. It is recommended to re-lift lashes every 6-8 weeks (when the client’s lashes are new) depending on the clients growth cycle and aftercare. The faster the natural lashes grow, the sooner the lash lift will grow out. To maintain neat and lifted lashes, the natural lashes will have to be re-lifted 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
- Antidepressants
- 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
- Steroids
- Tamoxifen blocks the estrogen receptor to prevent breast cancer.
- Thyroid medications
- Weight loss drugs
Clients who are on medication are still suitable for lash lifts, 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
Hormones
Natural lash growth is regulated by hormones – androgens, estrogens, thyroid and parathyroid hormones, prolactin, corticosteroids, somatotropin and melatonin.
The most crucial hormone contributing to lash 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.
Vitamins
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.
Age
There are so many changes that happen as the body ages, affecting the lash growth cycle and health of the lashes. It is entirely normal for lashes to start thinning as we age. The lash growth cycle can slow down or completely stop due to a drop in certain hormones. The skin surrounding the lashes become drier, which prevents the lashes 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. Lashes get weaker and thinner with age as hormone levels and building blocks for hair growth decreases. Older clientele should be lifted with caution, as the natural lashes are weaker. Lifting weak lashes can damage the lashes.
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 lashes. Some women notice quicker growth and shinier lashes by week 20 of pregnancy. Extensions will grow out quicker due to the growth cycle speeding up, and extensions may not last as long as the natural lashes can become oilier. In other cases, lashes can also become drier and more brittle, resulting in them breaking.
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. Lash (and 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, and how often they'll need a re-lift. It's important to discuss with your client to ensure that they're aware of the results, retention and frequency for refills to maintain their sets.