What Are Lipid Soluble Hormones?

Elite HRT

Written by Elite HRT on April 05, 2021

Medically reviewed by

Camille Frecking, Regulatory Affairs Specialist, MEDICAL ADVISOR

Hormones are often an overlooked aspect of people’s well being. Many choose to focus on eating healthy and exercising to improve their cardiovascular and muscular health, but while these can improve your overall wellbeing, leaving out your hormonal health could leave some opportunity for improvement to be missed.

Hormones are signaling chemicals that are found throughout the body, and hormone levels impact nearly every body system in some capacity from insulin regulation (think blood glucose levels) to melatonin release (think sleep cycles).

While the nervous system is able to signal immediate changes in the body, hormones released by the endocrine system are much more potent and long-lasting in their effects when it comes to the processes they trigger.

With such far-reaching implications, ensuring your body has a healthy hormonal balance is essential when undertaking the journey of health and wellness.

Below is a closer look at lipid-soluble hormones. Knowing what lipid hormones are, how they work, how they impact the body, and ways you can support a healthy hormonal balance can allow you to take your health and wellness to the next level.

Solubility of Hormones

While hormones are a categorization of signaling molecules in the body, they can be further broken down into two subcategories which are water-soluble and lipid-soluble hormones. The subcategories signify what medium they are readily dissolved in.

Water Soluble

Water-soluble hormones include amine, peptide, and protein hormones. These molecules typically have a charge on their structure which allows them to readily dissolve in water. This is beneficial in getting the hormones into the bloodstream, which is made of a large percentage of water.

While these hormones are readily transported through the bloodstream, they are typically unable to cross the plasma membranes of cells due to their charged substituents. Because of this, the protein hormone binds with cell surface receptors that initiate a signaling cascade within the cell. This enables water-soluble hormones to effectively cause physiological change without actually getting into the cell’s cytoplasm or anywhere near the nucleus.

Lipid Soluble

While protein-based hormones are able to circulate freely throughout the body, lipid-soluble hormones require shuttles to get them to their destinations. These shuttles are proteins found within the blood that allows lipid-derived hormones to attach and hitch a ride through the bloodstream.

Some of these proteins include sex hormone binding globulin (SHBG), corticosteroid binding globulin (CBG), thyroid binding globulin (TBG), and transthyretin (TTR).

Lipid soluble hormones may need assistance with transport, but they are incredibly good at crossing the lipid bilayer of cell membranes and directly signaling changes at a cellular level.

Lipid soluble hormones are typically longer lasting and have a slower onset than other hormones. 

Because of this, lipid-soluble hormones are typically thought of as slow-acting hormones while water-soluble are typically faster acting.

Examples of Lipid Soluble Hormones

There are many different lipid-soluble hormones within the human body. While they differ in their function, they all share a similar structure. The main distinguishing feature is that their structures are uncharged, which results in them being non-polar.

Below is a look at five different lipid-soluble hormones within the human body and how they interact within it.

Testosterone

Testosterone is the main sex hormone found in men. The hormone is mainly produced in the testicles by Leydig cells. The formation of testosterone starts with a cholesterol molecule that is then modified by the cells within the gland. This process occurs mainly in the testis but also occurs in small amounts in the adrenal glands of both men and women.

In men, testosterone synthesis occurs throughout life. This constant synthesis can see a dip as you get into later stages of life and can result in physiological and psychological changes. Decreased libido, decrease in muscle mass, and changes in fat distribution are all common changes that occur due to testosterone decline.

While this trend is observed, some people have higher levels of testosterone even as they age. These differences from person to person can be a result of a number of different factors including both internal and external factors. Hormone replacement therapy can allow those that experience decreases in testosterone to live a better quality of life and have a steady testosterone balance.

Estrogen

Estrogen is the main sex hormone found in females and it serves a vital function in the menstrual cycle, development, strong bones, and pregnancy. The hormone is produced by the granulosa cells in the ovaries and small amounts are produced in the adrenal glands. Like testosterone synthesis, estrogen is derived from cholesterol and is modified to create estrogen.

Unlike testosterone in men, estrogen levels in women change throughout life in a cyclical fashion. The changes in hormonal concentration are what allows for the menstrual cycle to occur which is what allows women to bear children.

The cyclical changes in estrogen are only present during the years that you are actively menstruating. As women age, the number of eggs within the ovaries begins to diminish which signals menopause to occur. During menopause, menstruation halts, and the cyclical pattern of estrogen levels stops. Symptoms like hot flashes can be experienced during this time.

Progesterone

Progesterone is a supplemental hormone in women that is vital to reproductive functioning. Progesterone is also released in a cyclical fashion and increases after ovulation and before menstruation. Progesterone is actually released from the corpus luteum, a mass of cells that was once a follicle that released an egg in ovulation.

This temporary structure releases progesterone to help with preparing the uterus for implantation. When progesterone has released the lining of the uterus begins to build and thicken. If an egg becomes fertilized it will be able to implant in the lining of the uterus so that it can grow.

If implantation occurs, the corpus luteum will continue to make progesterone, until the placenta develops. The placenta will then take over the progesterone production so that the uterine wall stays large enough to support the fetus.

Cortisol

Cortisol is a steroid hormone that is within both sexes. It is produced within the adrenal glands and is an important player in the stress response. 

Adrenaline is most commonly associated with the stress response as it is responsible for the elevation of heart rate and increased respiration. Cortisol acts alongside adrenaline and has much longer-lasting effects on the body than its fast-acting water-soluble counterpart. 

Cortisol acts by increasing the amount of available energy in the blood while also suppressing processes that are not immediately necessary like the immune response and digestion. These responses are ideal when your body needs to divert its resources to your muscles and brain to tackle stress or immediate threat.

While the stress response in the human body is great at preparing the body to fight or flee, it is sometimes not very good at discerning the difference between threats and the regular stresses of life. People who have chronic stressors actually are at risk for health complications because the body is constantly secreting stress hormones like cortisol. The result is prolonged suppression of some bodily systems which are necessary for optimal functioning. 

Prolonged elevation of cortisol levels can be effectively mitigated through stress management and learning how to cope with stress. 

Aldosterone

Aldosterone is another lipid-soluble hormone that is created by the adrenal gland. Aldosterone plays a pivotal role in the maintenance of fluid balance in the body. 

The kidneys are the main organ that is responsible for maintaining a healthy fluid level and blood volume. The kidneys work by filtering blood and facilitating the excretion of waste products like urea and excess salts. The fluid that leaves the kidneys is urine and transferred through the ureter to the bladder where it is held until you urinate. 

Aldosterone is the hormone that is responsible for increasing water reabsorption within the kidneys. In other words, aldosterone acts by limiting the amount of water loss through the kidneys. During events of dehydration, low blood pressure, or blood loss, aldosterone is secreted as a way of conserving water and fluids within the body. 

Conclusion

In summary, lipid-soluble hormones play an important role within the human body. Although they need some assistance traveling through the bloodstream, they are very effective at inciting cellular changes within the human body. 

Testosterone, estrogen, progesterone, cortisol, and aldosterone are all lipid-soluble hormones that the body needs to function optimally. While the body is fantastic at maintaining a healthy hormonal balance, it can occasionally need assistance through the assistance of hormone supplementation. Ensuring your hormonal health is at its best is a great way to facilitate a great quality of life.

Elite HRT is here to help you every step of the way to ensure your body has the hormonal balance it needs to function at its very best. 

Resources

Blood Components | Community Blood Center

Endocrine System : Types of Hormones | Tulane Universty

28.1 Types of Hormones | Texas Education Agency

Testosterone Synthesis – an overview | Science Direct

Granulosa Cell – an overview | Science Direct

Actions, Delivery, Transport of Hormones | Tulane University