What Is Androgenetic Alopecia? One Type of Hair Loss Explained
Alopecia is a general medical term for hair loss, with androgenetic alopecia — aka AGA — being one specific kind.
Read on to get the full scoop on this common form of hair loss, including causes, treatments and information on the best natural hair wellness products.
So What Is Androgenetic Alopecia, Exactly?
“Androgenetic alopecia is a common form of hair loss,” said Dr. Stephanie Nichols, a licensed naturopathic physician specializing in autoimmunity and endocrinology.
It affects both men and women, though males and females typically have different experiences with the condition. You’ve probably heard the commonly used colloquial names for AGA, “male pattern baldness” or “male pattern hair loss.” Not surprisingly, in women, it’s also called “female pattern baldness” and “female pattern hair loss.”
Other forms of alopecia that you may have heard of are:
These other types of hair loss are distinctly different from AGA, both in their underlying causes and the ways they affect hair.
What Causes Androgenetic Alopecia?
Hair loss in men and women with AGA is believed to be caused by hair follicles’ increased sensitivity to androgens, a group of hormones that are probably best known for their role in developing characteristically male traits and reproductive activity. But androgens are important hormones made by both men and women, and they play an important role in the regulation of hair growth.
“As the name suggests, androgenetic alopecia has two main factors at play — genetics and hormones,” explained Dr. Harshal Ranglani, a clinical dermatologist.
In people who are experiencing androgenetic alopecia, high levels of an androgen called dihydrotestosterone (DHT) are involved in causing hair loss, but the root cause of AGA is a little more complex and not yet fully understood. “It is thought that hair follicle sensitivity to hormones may trigger hair thinning in a genetically susceptible individual," said Dr. Ranglani.
Researchers suspect that this type of alopecia is inherited and involves several different genes. For men with AGA, one particular gene, the AR gene, seems to play a major role. However, studies have not shown the same genetic difference in women. The mechanisms that are the cause of hair loss in women are less understood, and the degree to which androgens play a role is less clear. In fact, even the name “androgenetic alopecia” is often replaced with “female pattern hair loss” to underscore the difference.
Aside from genetics, AGA can result from underlying medical conditions. Men and women may experience androgenetic alopecia caused by an endocrine condition or an androgen-secreting tumor.
For men, AGA is often associated with other medical conditions like coronary heart disease and enlargement of the prostate or prostate cancer. Diabetes, obesity, and high blood pressure have also been linked to AGA.
“We often see it in women with hormonal conditions like polycystic ovarian syndrome (PCOS), hyperprolactinemia, and hypothyroidism,” said Dr. Ranglani. “Environmental factors such as stress, poor nutrition, smoking and lack of sleep can accelerate this hair thinning,” she said.
What Are the Symptoms of Androgenetic Alopecia?
The main symptom of androgenetic alopecia is hair thinning and shedding. “There are no symptoms of pain or itching associated with such hair thinning. Patients often come into the clinic complaining that their scalp is prominently visible,” said Dr. Ranglani.
How Is AGA Different For Men and Women?
While AGA can start any time after puberty for both men and women, men often experience early-onset androgenetic alopecia starting in their teens or early 20s. For women, the onset of AGA is typically much later, with many women seeing their onset start in and around menopause. In fact, less than 60% of women aged 69 or older have a full head of hair.
Another major difference between men and women is the areas of the scalp affected. “The pattern of androgenetic alopecia varies in men and women,” said Dr. Ranglani. In androgenetic alopecia in men, thinning typically happens at the front of the head, producing a characteristic “M” shape as the hairline recedes on either side, along with a thinning crown.
“In females, rather than frontal hairline thinning, what we see is widening of the midpart of the hair, causing the scalp to be visible," said Dr. Ranglani. "This progressively widens.” In other words, hair loss for women often radiates out from the part. Female pattern hair loss also tends to be a more diffuse loss, as compared to men, and women often won’t experience full-on balding the way men do.
Female pattern hair loss is categorized into three types, according to the Ludwig Classification:
- Type I: A small amount of thinning that can be hidden with hairstyling techniques.
- Type II: A widening part and decreased volume.
- Type III: A thinning throughout the head, with noticeable thinning on the crown.
What Happens To Hair Follicles?
Hair growth happens in different cycles or stages. With AGA, the active stage of the hair growth cycle (called the anagen stage) gets cut off prematurely. Normally, the anagen phase lasts anywhere from two to six years, but androgenetic alopecia causes the cycle to become shorter and shorter from cycle to cycle. Not only that, but it also takes longer for new hair to start growing back after it is shed. This is because the hair follicles are undergoing a physical change called miniaturization, in which the hair follicles shrink in size and reduce the thickness of hairs along with them.
Miniaturization happens because, for those with AGA, some hair follicles seem to be genetically oversensitive to dihydrotestosterone (DHT), which is a hormone that is converted from testosterone with the help of an enzyme in the follicle’s oil glands. DHT binds to the oversensitive receptors in the hair follicle and shrinks it over time.
“In androgenetic alopecia, dihydrotestosterone (the active form of testosterone) also causes a decrease in the growth phase of the hair, making each hair progressively thinner with each hair cycle," Dr. Ranglani said. "Ultimately, what results is thin, fine, 'vellus' hair.”
And eventually, the follicle might stop producing hair altogether.
Is Miniaturization Reversible?
The not-so-satisfying answer? It depends.
Miniaturization isn’t just a process of shrinking — there is damage to the follicle as well. "It is reversible if treated early. [However], if maximal miniaturization has occurred, the hair follicles will be unable to recover and grow back,” said Dr. Ranglani.
While you might be able to stop the miniaturization process with oral and/or topical drug treatment, and possibly even encourage hair regrowth, most people need to stay on these treatments long-term to keep from losing their hair again.
How Is Androgenetic Alopecia Diagnosed?
If you think you’re experiencing androgenetic alopecia, it’s important to see your doctor since hair loss can be the symptom of a more severe illness or condition. Your doctor will talk to you about your general health and ask about other symptoms you might be experiencing. Your clinician might also want to do a blood test to check your levels of thyroid hormone, androgens, iron or other substances that can affect hair growth.
“Sometimes, we may use a specialized instrument called a trichoscope to evaluate the extent of hair follicle thinning and to decide the best course of treatment," said Dr. Ranglani.
What About Treatment?
“The best treatments are based on stopping this miniaturization before the loss of the follicle,” explained Dr. Lisa Rhodes, a board-certified dermatologist at Westlake Dermatology.
There are several ways a doctor might approach treatment of androgenetic alopecia. According to the Journal of the American Academy of Dermatology, the most common treatment options include medications such as:
- Minoxidil (topical)
- Finasteride (oral)
- Dutasteride (oral)
- Spironolactone (oral)
You’re probably already familiar with minoxidil as the active ingredient in the hair loss treatment sold as Rogaine. Minoxidil is a topical treatment applied directly to the scalp, and it’s often the first line of defense in treating AGA.
It increases the length of time follicles spend in the active anagen phase of growth, and it “wakes up” follicles that are in the inactive catagen stage. The fine vellus hairs, which become increasingly common as follicles shrink, grow back into thicker terminal hairs as minoxidil helps enlarge follicles. In addition, shedding is reduced. Sounds promising. But how does minoxidil do it?
The exact mechanisms of action in minoxidil aren’t known since this drug was developed to treat high blood pressure. When patients taking the drug orally started seeing increased hair growth, a topical form of minoxidil was developed for hair loss.
Research has shown that minoxidil can be effective for hair loss, though hair loss will recur if it’s not applied daily or stopped. Aside from an irritated scalp, 3%-5% of women using minoxidil might notice excessive hair growth on their face. Though rare, other side effects could include dizziness, fast/irregular heartbeat, fainting, chest pain, swelling of hands/feet, unusual weight gain, tiredness and difficulty breathing, especially when lying down.
Finasteride (Propecia) and Dutasteride (Adovart)
Finasteride and dutasteride are 5α-reductase (or 5-alpha reductase) inhibitors that prevent the conversion of testosterone to DHT and the resulting damage to follicles. It has been shown that these drugs act in a similar way to minoxidil by slowing down or preventing further hair loss, and they could stimulate regrowth from follicles that have been dormant but are still viable. Like most treatments, these drugs can’t revive follicles that have already become inactive.
These medications need to be taken daily and for the long term in order to be effective. Once stopped, hair loss and follicle miniaturization will begin again. Not only that, but their effectiveness might decrease over time.
While these medications are more commonly used in men with AGA, and there is more research supporting their efficacy and side effects, research does suggest that they might be effective for women, too, particularly those under 50. These drugs are to be completely avoided by women who are pregnant or might become pregnant as they are known to cause birth defects, with risk factors continuing for months after the drug is stopped. Even handling dutasteride can pose risks to pregnant women and their fetuses.
Both dutasteride and finasteride can come along with some not-so-fun side effects in men, but these drugs haven’t been studied as extensively in women. Some reported side effects in women include headache, irregular menstruation, dizziness and increased body hair.
Spironolactone is another drug that’s used primarily for heart-related issues, specifically high blood pressure and heart failure. Common “off-label” uses are in treating female acne and polycystic ovarian syndrome (PCOS), and because it’s a weak androgen receptor inhibitor, it’s now commonly used to treat female hair loss as well. There hasn’t been a lot of research looking specifically at female hair loss as yet, and though it has shown promise — on its own and in combination with minoxidil —it can cause side effects like dizziness, tender breasts, menstrual spotting, nausea and electrolyte imbalances. In rare cases, it even causes hair loss.
Other Treatments For Androgenetic Alopecia
Aside from topical and oral medications, there are alternative therapies for people dealing with androgenetic alopecia. “Other approaches to treat this issue include promoting the health of the follicle, such as laser hats and combs and PRP (platelet-rich plasma) injections,” said Dr. Rhodes.
Laser treatments are showing promise as a way to stimulate hair growth, with minor irritation and itching being the most common side effects. While more research is needed, laser treatments could provide a viable alternative to pharmaceuticals.
Scalp platelet-rich plasma (PRP) is a process that collects plasma from your blood in order to inject it into the scalp to promote hair growth. It’s a relatively new procedure that has shown promise as a potential hair loss treatment.
When all else fails, Dr. Rhodes said that the only solution is hair transplantation. "During this procedure, hormone-insensitive follicles are transplanted into the thinning areas," said Dr. Rhodes. "Once transplanted, they retain their insensitivity to hormone miniaturization and stay full caliber.”
Tips For Recovery and Healthy Regrowth
Taking care of your general health and well-being cannot be underestimated when it comes to promoting hair regrowth. To that end, here are some tips to consider.
Eat A Healthy Diet
“Ensure that your diet is rich in protein, vitamins and minerals (especially iron) as these are needed for optimal hair regrowth,” said Dr. Ranglani. There are so many upsides to eating a healthy and balanced diet since it’s a building block for full-body health, not just hair regrowth.
Aside from diet, stress is another major player when it comes to hair loss. “Although easier said than done, try to minimize stress as much as possible because stress causes hormones to go haywire, often delaying hair regrowth,” said Dr. Ranglani.
“I recommend mindfulness and relaxation exercises, a healthy diet rich in biotin, and herbal remedies like saw palmetto to treat androgenetic alopecia,” said Dr. Nichols.
Another important part of being more Zen when it comes to hair loss is patience. It takes time for hormones and hair growth cycles to rebound, so breathe deep and give it time. “Be consistent with hair regrowth treatments; it takes quite some time to see substantial improvement,” said Dr. Ranglani.
When tending to your hair, avoid excessive or aggressive styling. If you’re experiencing AGA, color or other chemical treatments should probably be put on hold. Try giving yourself a gentle scalp massage while working in your favorite shampoo with your fingertips or a scalp massager for extra relaxation.
Join a Hair Wellness Community
Hair loss isn't easy. At VEGAMOUR, we create products that help you feel your best on the outside, but we are here to support you on your emotional journey, too. We've created this private Facebook group for women on hair wellness journeys just like you. This group is a safe space to learn and share with others, tell your story, swap tips you've learned or just read what others are posting. You don't have to go it alone — we hope you'll join us.
On its own, androgenetic alopecia might not be a serious or life-threatening condition, but hair loss can be so tough to deal with — both emotionally and psychologically. So perhaps the most important thing you can do on your hair regrowth journey is to be kind to yourself!
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