Bioidentical Hormone Replacement Therapy (BHRT) is very popular and useful for so many people.  We often prescribe BHRT for the following conditions:

• Menopausal symptoms
• PCOS
• PMS
• Perimenopause
• Estrogen dominance
• Progesterone insufficiency
• Vaginal atrophy
• Anti-aging
• Low testosterone
• Low libido
• Acne
• Osteoporosis/osteopenia

This list is not a comprehensive list but gives you an idea of what BHRT can be used for. Bioidentical hormone applications come in many forms, with transdermal creams being the most common.  There is a lot of conflicting information on where to apply hormone creams. We recommend to all of our patients to apply hormone cream to the inner thigh. 

Whether you are using progesterone cream, estradiol, estriol, biest, testosterone, or DHEA creams, the inner thigh is typically the best place to apply the cream. Whether you are male or female, the inner thigh is the proper location to apply your cream. You can also apply BHRT cream to the back of the knee, which I will further explain.   

Absorbability and longer lasting:

Hormones are all fat-soluble because they are derived from cholesterol.  The inner thigh has a good amount of fat tissue, and it has soft, thin skin compared to other areas of your body.  This makes it absorb more easily into the skin. Also, because it has a nice fat pad, the release of the hormone will last longer.   For example, the inner part of your forearm has thin skin but very little fat. So it will be absorbed quickly, but because of the lack of fat, it will not last long.  

Sharing your cream inadvertently:

If you apply your hormone cream to the inner thigh, that prevents “sharing it” with others.  If you put your BHRT cream on the inner forearm, then it can get on other people or pets.

For example, I had a patient, “Mary” that came to me complaining that her 3-year-old granddaughter, “Austin” was growing pubic hair.  Mary and her husband “Rick” were the legal guardians of Austin. Mary was worried that past abuse might have caused this and wondered if it was precocious puberty.  I knew that Rick was seeing a colleague of mine and taking testosterone cream for his diagnosis of Low-T. I asked her, ‘does Rick put his testosterone cream on his arms?’

Mary understood right away. She told me, not only does Rick slather testosterone cream all over his inner arms. But as soon as Austin wakes up in the morning, the first thing she does is run to grandpa and give him a great big hug.  We did the testing for precocious puberty to be thorough. But as soon as Rick started applying his testosterone cream to his inner thigh, Austin’s pubic hair went away.

Testosterone cream for Low T therapy is potent and quite a large dose.  Testosterone cream dosing for a man could be from 100mg-200mg twice a day.  The dosage might be proper for a male. But trust me the daily dose that a man receives for Low-T is way more testosterone than us females make in a lifetime.

Like I had mentioned hormone cream is best absorbed in fatty tissue.  The bum/derriere/fanny/tush is also a great fat pad to absorb hormone cream.  But (haha) if you apply it to your bum and then share the same bathroom with other people.  Then you are sharing your hormones with others. Another example, Anne came to see me, and I could see this 46-year-old female had acne all over her cheeks, chin, and jawline.  

She thought it was the hormones I was giving her and complained that she was very cranky (testy).  Her testosterone levels in her blood were four times higher than they should, and she was not taking testosterone.  Well, she was because her husband John was putting his testosterone on his bum and they shared the same toilet seat.         

Applying hormone cream to your arms can also get on pets and babies.  Pets and babies are a lot smaller than us adults. So even a low dose of progesterone or biest can be way too much for little animals or kids.  By putting the BHRT cream on your inner thigh, will ensure it doesn’t get on children, babies or pets.

Do not put cream anywhere near your breast tissue:

Bioidentical hormone creams can migrate to other adjacent areas.  If you apply your hormone cream to your upper arm, shoulders, or chest, you can inadvertently get it on your breast tissue.  It can migrate to your axillary area (armpits) which has breast tissue, which is very responsive to hormones. I never want hormones near the breast tissue.

Abdomen:

The abdominal tissue is very different from other parts of the body.  I consider abdominal tissue to be “volatile.” The adipose (fat) cells in the abdominal area can secrete its own hormones.  While it is or can be a “fatty area,” I do not think this is a good place to be applying BHRT cream. Also as mentioned above, the cream can migrate.  If you apply hormone cream to the stomach, it can travel up to the breast tissue. Whether you are a man or woman, I do not want any hormones near the breast tissue.  

Transvaginal application:  

Some sources tell you to apply hormone cream to the vaginal tissues.  Applying hormones to the vaginal tissues will cause instantaneous absorption.  But the lastability is diminished.

Testosterone: Be careful applying testosterone to the vaginal tissues as it can cause the clitoral growth.  It can help with instant libido but do not apply transvaginally daily as in some females it can cause the clitoris to grow in size.

Vaginal atrophy:

Applying estriol to the vaginal tissues can be very helpful for vaginal atrophy, vaginal dryness or pain with intercourse from menopause or lack of estrogen. If you are applying BHRT cream to the vaginal tissues make sure the cream is intended for the vaginal tissue because some creams made for skin can cause irritation.  

Testosterone cream and hair growth:

A few years ago, I had a new patient named Liz came to see me about BHRT.  She was already on hormones from another doctor but was not satisfied with the care she was getting. I remember sitting across from her and noticing she had a lot of long, thick black hair on her forearms.  

Having hair on your forearms is normal for females, and if you have dark hair like me, then you have dark hair everywhere else.  I asked Liz, ‘do you apply your testosterone cream to your arms?’. And she replied, ‘yes.’

Testosterone will grow hair in the area that you apply it.  And if you have dark hair and come from a background that has more body hair like Liz, then that testosterone is going to make the hair darker and hairier.  

However, as I said, it will grow hair only where you apply it. If you apply it to your bum, arms or anywhere that has hair follicles, then the hair will grow there.  If you apply testosterone to your inner thigh and it grows hair, then you can shave it off. A quick side note: if you apply testosterone to your head, it will not grow more hair there.  

What if I don’t want/can’t apply hormone cream to my inner thigh?

I have had some women that have had laser hair removal on their thighs and are worried about the hair growing back from testosterone cream.  I had one patient that went for her usual monthly bikini wax. Her waxer exclaimed, ‘what happened!” The testosterone cream caused her upper thighs and bikini areas to explode in dark hair.  In these cases, you can apply testosterone cream to the back of the knee. The back of the knee has a nice fat pad but no hair follicles. If you do this, be careful of shorts and chairs (especially leather/pleather) and wearing shorts/skirts.  That way you do not “share” your hormone cream with others.

Estriol (E3): 

An exception to apply your hormone cream to the inner thigh is in the case of estriol.  There are three bioidentical estrogens: estrone, estradiol, and estriol. Estriol (E3) is the most gentle of the estrogens and very good for skin.  As mentioned above it is helpful for vaginal atrophy. But it is also great for skin. The majority of my patient population are females. And I will tell you and 99% of them are concerned with facial wrinkles.  Estriol topically to the face is great for wrinkles, hydration, and building collagen.

Dermal adaptation:  

Many sources will tell you to rotate the areas that you apply your hormone cream.  This is not necessary. If you apply it in the same area daily, you will not get dermal adaptation.  In fact, rotating it can cause changes in absorbance making the dosage differ. For example, the skin of your inner thigh is different from the skin of your lower back. So the absorbency of the dose can vary from area to area.  

Skin Absorbency of BHRT cream: 

Some people will not absorb the cream as easily as others, which gives BHRT cream a bad name.  I have had patients complain they do not want a hormone cream because “it doesn’t work.” BHRT cream does work, but absorbency differs person to person.  Some people have thicker skin than others.

Men typically have thicker skin and more hair, making it difficult for the hormone cream to be absorbed.  For people that have thicker skin or a tough time absorbing the BHRT cream, I have the compounding pharmacy add in DMSO, which can penetrate through membranes easily.  By having the compound pharmacy add in a small amount of DMSO to the BHRT cream, it allows for enhanced absorbability of the hormone cream.

I hope this blog on where to apply your BHRT cream was helpful.  If you have any questions, please feel free to leave a comment below or send us an email at [email protected]