Types of Hormones
Hormones & Fertility
Signs of Hormone Imbalance
Confirmed Hormonal Imbalance
Hormonal balance is necessary to get pregnant, carry to term and have a healthy baby. Do you ever wonder if you have a hormonal imbalance? Hormonal imbalance does not happen overnight. It happens slowly over time.
We live in a fast-paced world, full of high demand. That demand puts a lot of stress on the body. Life’s demands puts our dietary habits low on the priority list. On top of that, we are exposed to more human-made chemical toxins than at any other time in the history of the human species. Most hormonal imbalances are a reflection of lifestyle choices over a long-period of time, perhaps months, years and decades. Fertility problems are often directly linked to a hormonal imbalance. In order to bring our bodies back to a fertile state, we must change how we view our lives. We must take time to nurture ourselves.
What exactly does hormonal balance mean for our fertility health? What do hormones do anyway? Does hormonal balance really matter? Absolutely! If our hormone levels are not balanced, our health will suffer. We cannot live without hormones. Hormones deliver messages. Our cells are genetically programmed to only receive and respond to messages from certain hormones. Each cell in the body contains hormone receptor cites. Once a hormone fits into a cell’s receptor, it gives the cell instructions. This is similar to a key fitting in a lock. Hormones control our bodily processes. Hormones are coordinated by the endocrine system. Without proper endocrine function, our bodies cannot maintain proper hormonal balance.
Hormone levels can be influenced by stress, fluid changes in the body, vitamin and minerals levels, infection, exposure to environmental toxins and the amount of body fat we have. Each endocrine gland plays a specific role in the ability of our body to maintain proper function. Each endocrine gland also communicates with the other in an amazing design. If one of the endocrine glands is not functioning properly, it may cause a broken link in communication with other endocrine glands or actions of the body, which may greatly impair fertility. Because the endocrine glands secrete hormones, and the hormones are messengers for actions within the body, if the gland is not functioning properly, hormonal imbalance occurs and the ability to reproduce may be impaired.
Different Types of Hormones: Natural and Synthetic
The hormones produced by our bodies are known as steroid hormones. There are also bioidentical hormones, derived from natural sources that are duplicates of steroid hormones. Hormones prescribed by doctors are man-made and are not found in nature. These are commonly used for hormone replacement therapy (HRT), birth control and artificial reproductive technology (ART).
Steroid Hormones: These are natural hormones our bodies produce.
Natural Bioidentical Hormones: Estrone, estradiol, and progesterone are currently approved by the FDA. Testosterone and DHEA have limited availability in the US. Some countries do not approve bioidentical hormones. Bioidentical hormones are isolated from plants, minerals or animal sources and are considered natural because of this. Bioidentical hormones are duplicates of steroid hormones.
Synthetic Hormones: These hormones are made in a lab. They are patented medications. These types of hormones have a similar effect to our own endogenous hormones. They are commonly used for hormone replacement therapy (HRT) and artificial reproductive technology (ART). The most common use of synthetic hormones is birth control.
Hormones Important for Reproductive Function
There are key hormones that directly affect fertility health in both men and women. There are many different hormones in the body, so I am only going to cover the major players; the hormones most commonly out-of-balance and their role in fertility health.
Important Hormones in Women of Childbearing Age: The Basics
- Estradiol (E2 estrogen): Estradiol is produced primarily by the follicles and corpus luteum (remnant egg sac) in the ovaries. This estrogen is the most potent and abundant. Estrogen is essential for healthy bone formation, healthy gene expression, maintaining healthy cholesterol levels, and formation of secondary sexual characteristics (pubic hair, breasts, ect). Estradiol is vital for a healthy menstrual cycle.
Progesterone: Progesterone is needed for healthy libido, bone formation and proper blood clotting. Progesterone is produced by the corpus luteum in the ovaries and by the adrenal glands. Progesterone is one of the main hormones in helping to regulate the menstrual cycle. It works to balance the effects of estrogen. Progesterone also signals the release of insulin, playing a role a person’s susceptibility for diabetes or insulin resistant PCOS. Adequate levels of progesterone are vital for proper fallopian tube function. Almost all of your other hormones are made from progesterone. Progesterone is vital for conception and maintaining pregnancy. One of the main actions of progesterone is to help support a developing embryo. During pregnancy the placenta produces progesterone to help sustain the developing baby.
Luteinizing Hormone (LH): This hormone is produced in the anterior pituitary gland. LH surge is responsible for triggering ovulation and development of the corpus luteum. LH works synergistically with FSH. It stimulates other certain cells to produce testosterone.
Follicle Stimulating Hormone (FSH): This hormone is also released and synthesized by the anterior pituitary gland. It regulates the body’s development, growth and maturation. It also regulates reproductive processes. FSH works alongside with LH. FSH signals some of the follicles in the ovary to begin maturing in preparation for ovulation.
Cortisol: Produced by the adrenal glands, but controlled by the hypothalamus. Its primary function is to increase blood sugar, aid in fat, protein and carbohydrate metabolism and suppress the immune system. Cortisol is released in response to stress.
DHEA (dehydroepiandrosterone): DHEA is a precursor to testosterone and estrogens. This means that those hormones are made from it. DHEA is necessary for protein building and repair. It is made by the adrenal glands. DHEA levels decline dramatically as we age.
Testosterone: Testosterone in women is in much lower amounts than in men. It helps to support a healthy sex drive and build bones.
Important Hormones in Men
- Testosterone: Produced and secreted primarily by the testicles, but also a lower amount by the adrenals. It is vital for the development of the testis, prostate and secondary sexual characteristics in males. For example, increased muscle mass, bone and body hair. It also plays an important role in libido, sexual arousal, erection and is the key player in male fertility.
Estrogen: Men produce much lower levels of estrogen, but without estrogen, sexual arousal could not happen. Estrogen is responsible for many functions in the health of the body, in both men and women. Without appropriate levels in men, sexual function will be decreased. Too much estrogen may cause erectile dysfunction, low/lack libido, low sperm count, and lowered production of seminal fluid.
Progesterone: Produced by the adrenal glands and testes. Has similar actions for regulating certain body systems, just as it does in women, but of course does not have the same reproductive actions. Helps to balance estrogen levels. Regulates immune response and is anti-inflammatory. It normalizes blood clotting, vascular tone, and the mineral levels of zinc and copper. It also helps to regulate cell oxygen levels, and the use of fat stores for energy.
Luteinizing Hormone (LH): LH acts upon cells called Leydig cells within the testis, this action is responsible for the production of testosterone and plays a role in the creation of sperm.
Follicle Stimulating Hormone (FSH): This hormone stimulates primary spermatocytes to divide in the first stage of meiosis, which forms secondary spermatocytes. FSH plays a vital role in signaling spermatogenesis. This is the very beginning of the creation of sperm.
DHEA (dehydroepiandrosterone): DHEA has many of the same actions for the body as it does for women, but it vital in helping men maintain testosterone levels, which is important for sex drive and sustaining an erection.
Cortisol: Produced by the adrenal glands, but controlled by the hypothalamus. Its primary function is to increase blood sugar, aid in fat, protein and carbohydrate metabolism and suppress the immune system. Cortisol is released in response to stress.
Signs and Symptoms of Hormonal Imbalance
Symptoms of hormonal imbalance can be a blessing. This is because they are the body’s signals something needs to be changed.
Symptoms of Hormonal Imbalance in Women
Symptoms of Hormonal Balance in Men
Hormone Testing: Should I Get My Hormones Levels Tested?
If you checked off two or more of the above symptoms and you have been struggling to get pregnant or keep a pregnancy, it is important you get your hormone levels tested.
“The next major advance in the health of the people will be determined by what the individual is willing to do for himself.”
-John Knowles, Former President of the Rockefeller Foundation
What kind of test should I get? Saliva or Serum?
If you suspect hormonal imbalance, you have two options, one, purchase an at-home saliva test kit or schedule an appointment with your doctor to get a blood serum test done. Depending on what your symptoms are, you may only want to test certain hormones. If you are unsure which hormones could be out-of-balance, it may be best to get a full hormone panel run. We suggest you get the following hormone levels tested…
Sex hormone binding globulin:
24 hr. urinary free cortisol
Glucose Tolerance Test
Blood Lipid Profile
Glucose Tolerance Test
Saliva Hormone Testing
Dr. John Lee was very adamant that testing for hormones should be done through saliva testing, not blood testing (almost all doctors will test the blood).
You can order an at-home saliva test that you will take at a certain time during your cycle and then send away to a lab for analysis. They will then mail back the results so you can find out if you have any hormonal imbalances. You can order FDA approved home hormone tests here.
Blood Hormone Testing
While Dr. Lee was adamant about getting hormone testing through saliva, it may be more helpful to work with your doctor to get your hormones tested so they can explain the test results to you, even if it is a blood test. Women most likely will have the tests performed a couple different times in a cycle, since hormone levels change throughout the menstrual cycle. This can give you insight to your entire hormonal profile.
We have women come to us daily asking us to interpret their hormone test results. Remember, it is extremely important to have your doctor explain what your test results mean for your health and fertility.
How Does Hormonal Imbalance Happen?
Research shows that stress boosts levels of stress hormones such as cortisol, which inhibits the body’s main sex hormones GnRH (gonadotropin releasing hormone) and subsequently suppresses ovulation, sexual activity and sperm count.
GnRH is responsible for the release of Luteinizing hormone and follicle-stimulating hormones by the pituitary, the suppression of testosterone, estrogens, and sexual behavior.
Chronic stress may cause lack of libido as well as a decrease in general fertility. Chronic stress may cause adrenal fatigue and thyroid problems.
The body is extremely sensitive to vitamin, mineral and fluid levels. If you are not eating healthy whole foods daily, your body cannot function properly. In addition, if you are eating foods that are unhealthy, full of preservatives, dyes and other human-made processed chemicals, you may be damaging your endocrine glands, causing hormonal imbalance. Many food additives are xenohormones. We need whole foods, in their natural state to support hormonal balance. We also need clean filtered drinking water to sustain fluid levels and flush toxins.
Xenohormones are human-made chemicals. These chemicals have the ability to interfere with the natural functions and development of our bodies. Not only can they mimic our natural hormones, but they can block other hormones from binding to receptor sites. All xenohormones are endocrine disruptors. They can alter how natural hormones are produced, metabolized and eliminated.
Common Sources of Xenohormones:
- Solvents & Adhesives (paint, nail polish, household cleaners)
- Non-organic meats (they are given hormones to fatten the up or to grow quicker)
- Pesticides, herbicides, fungicides
- Emulsifiers in soap and cosmetics
- PCD’s from industrial waste
- Hormonal birth control (pill, shot, ring, implant)
You can absorb xenohormones by ingestion, inhalation and direct skin contact.
People that lead high-stress lives, are sedentary, have sleep disturbance or who choose to regularly consume too much sugar, alcoholic beverages, smoke or take drugs, including many medications, may be causing hormonal imbalance in the body.
Scientific researchers are working on the connection to genetic predisposition in regard to hormonal imbalances. They do know that there are genetic links to obesity, diabetes, autoimmune disease and cardiovascular disease just to name a few, which may be caused by hormonal imbalance or cause hormonal imbalances.
Body fat cells, called adipocytes produce and store estrogen. Women who do not have adequate amounts of body fat may have menstrual cycle irregularities, anovulation and infertility problems. Low body fat may cause ovulation to stop.
Obese people may have too much estrogen due to too much body fat, which may also contribute to fertility. This is known as estrogen dominance. Obesity in men lowers testosterone levels. Chronic low levels of testosterone affect how the testis function, which causes all hormones produced by them, to be out of balance. Research shows elevated levels of estrogen in obese men. The sperm of obese men are often abnormal, this increases risk for miscarriage and chromosomal defects in a developing embryo. Obese men also often have sexual dysfunction.
Huge hormone changes begin to take place as a woman ages. Between the ages of 40-60 hormone levels begin to change in preparation for menopause and to allow the body to go through menopause. This takes many years. Perimenopause and menopause hormone changes are completely normal, though they make the body feel out-of-sorts.
Natural Therapies for Hormonal Imbalance
Eat a Nutrient Dense Fertility Diet
The best way to support balanced hormones is to eat a nutritious whole foods diet. The building blocks for hormones are found in the foods we eat. Just as nutrients in food can be helpful for fertility, there are some foods and chemicals added to foods that can be harmful for your healthy and fertility. What you eat, when you eat and how you eat are essential to maintaining hormonal balance. Learn how to eat a fertility diet here…
Regular exercise strengthens our muscles, builds stamina, may increase flexibility, increases circulation, keeps stress, depression and anxiety at bay, and promotes regular detoxification of excess hormones and toxins in the body. It is important to exercise for at least 30 minutes a day, 5 times a week. Make sure that the exercise you choose to do promotes sweat. Sweating is not only the body’s way to cool itself off, it is it’s way to naturally detoxify daily. All of this is very important for healthy hormonal balance and circulation to the reproductive organs.
Reduce Exposure to Endocrine Disruptors: Xenohormones
Ways to support healthy endocrine function and avoid xenohormones:
- Eat organic foods
- Avoid exposure to pesticides, herbicides and synthetic fertilizers
- Use natural feminine care products
- Use organic, natural body care products, including makeup
- Avoid food preservatives and dyes
- Use low VOC paints
- Use recycled unbleached paper products
- Use non-chlorinated oxygen based bleach in the laundry
- Avoid plastics
- Exercise regularly, be sure you are sweating during exercise
In 2005 the Environmental Working Group found 287 chemicals were present in the umbilical cords of human babies. Toxins included a variety of pesticides, waste from burning coal, gasoline, oil repellents in fast food packaging, by-products of synthetic fabrics and textiles, PFOA found in Teflon, and flame retardants. Of the 287 chemicals found, 217 are toxic to the brain and nervous system. 208 have caused birth defects and abnormal development in animal tests. 180 of the chemicals are known to cause cancer. This test proves that chemicals in our environment are directly ingested, breathed and absorbed by our bodies and then are directly passed on to our children.
Considering the information in the paragraph above, anyone who is concerned about their hormonal health should perform a bi-yearly cleanse. Fertility cleansing is specific to supporting fertility health. Fertility cleansing encourages the liver to cleanse the body of toxins and excess hormones. We encourage both partners to perform a Fertility Cleanse prior to trying to conceive. Over the years the body can accumulate toxins in the body from chemicals in the air, earth, water and from substances we put into our bodies. Many of these toxins get stored in the fat tissues of the body and can be released quicker through cleansing. A fertility cleanse is specific to the reproductive system and assists the body in eliminating the additional burden of substances not good for fertility or for the health of our future children.
Make a Stress Management Plan
Because stress can wreak havoc on our endocrine glands, causing hormonal disruption, keeping stress at bay is essential to promoting hormonal balance. A stress management plan is essential to balanced hormones. NO amount of herbs or supplements are going to be as effective if you are not managing stress. Learn how to make a stress management plan here…
Supplements for Hormonal Balance Support
- Whole food Multivitamin
Multivitamins serve as a type of “back up” plan to our diets. While eating a healthy fertility diet is of the utmost importance, it is always a good idea to include a whole food multivitamin in your program as well. Both partners should be taking a whole food multivitamin.
Depending on the type of hormonal imbalance you have, you may need to supplement with specific vitamins or minerals which directly support a certain endocrine glands function. For example, iodine is necessary to produce thyroid hormones.
Good Fats and Omega Essential Fatty Acids
Many fats are actually good for us, and are in fact essential to our good health. Fat intake is vital to healthy fertility. Instead of worrying about how much fat we eat, we need to be concerned with the types of fats we eat. We need a certain amount of saturated fats to produce cholesterol. Cholesterol is needed for formation of healthy cell membranes and is a precursor to all steroid hormones (progesterone, estrogen, FSH, ect). We cannot have proper hormonal balance without adequate amounts of saturated fats.
We also need balanced amounts of unsaturated fats. Essential fatty acids are three types of unsaturated good fats. There are three different types of unsaturated fatty acids; Omega-3, Omega-6 and Omega-9.
Royal Jelly is a substance that is secreted by nurse worker bees glands. Royal Jelly is rich in amino acids (29 to be exact), lipids, sugars, some vitamins, fatty acids and most importantly, proteins. It contains ample levels of iron and calcium. Royal Jelly also contains acetylcholine, which is needed to transmit nerve messages from cell to cell. It is beneficial to those individuals that suffer from a hormonal imbalance, as it helps to provide support to the endocrine system. It may also help with problems that are related to hormonal imbalance.
Adaptogen Herbs for Protecting & Nourishing the Endocrine System
Adaptogen is one of the many definitions for the therapeutic action a plant has. Adaptogen herbs are nourishing to the entire endocrine system. Adaptogens increase resistance to mind-body stress , enhance overall vitality and health. Plants recognized as adaptogens help to normalize the bodies functions even during diseased states, are non-toxic, nutritive, and have been deemed safe for long term use.
The goal in using adaptogens to promote hormonal balance is to support the endocrine system overall, the system in which hormones are made from and communicate with.
- American Ginseng root (Panax quinquefolius): American ginseng may support healthy sex drive, erectile dysfunction and enhance sexual performance in men. Strengthens the HPA (hypothalamus-pituitary-adrenal) axis, aiding hormonal balance, stress management, immune function.
Ashwagandha root (Withania somnifera): Supports overall endocrine system function. Supports proper immune response, aids in possible autoimmune fertility issues. Aids in supporting the body with proper stress response.
Eleuthero root and stem bark (Eleutherococcus senticosus): Supports overall endocrine function which supports hormonal balance. Strengthens the immune system. Great for people under severe stress. This herb helps people to feel better, perform better and recover from immune suppression more quickly.
Fo-ti, also known as Ho Shou Wu or He Shou Wu, root (Polygonum multiflorum): According to TCM Fo-ti helps to restore jing (life essence). Traditionally used for men who have low libido, low sperm count, erectile dysfunction and poor sperm motility. Supports fertility longevity. Supports both thyroid and adrenal function, both are extremely important and sensitive to stress.
Goji berry, dried fruit (Lycium barbarum,L.chinense): Studies show Goji protects sperm from hyperthermia (overheating), increasing hormone levels, sperm quantity and quality through its high antioxidant content. Supports hormonal balance through improved liver function support for both men and women. It is also extremely nutritious superfood.
Licorice root (Glycyrrhiza glabra): Supports the endocrine system for overall hormonal support. Licorice Rt. is an immunomodulator, stimulating immune system function in people with autoimmune disease. It is protective of liver health and supports proper inflammatory response.
Maca root (Lepidium meyenii): Helps to balance the hormones, but does not contain any hormones itself. It is able to do this by nourishing and balancing the endocrine system. Maca is a nourishing food for the endocrine system, aiding both the pituitary, adrenal, and thyroid glands (all involved in hormonal balance). Works to protect the body from stress damage. Shown to support and increase egg health. Shown to increase libido in both men and women.
Reishi mushroom (Ganoderma lucidum): Strengthens the immune system. Down-regulates excessive immune response (common in autoimmune disease), but enhances monocyte, macrophage, and T lymphocyte activity. Anti-inflammatory and stress support as well.
Rhodiola root (Rhodiola rosea): is an adaptogen, aiding the body in times of stress and change. Rhodiola is a potent antioxidant, working to protect the body from environmental toxins which may contribute to hormonal imbalance. Works to help prevent depression during hormonal changes. Its balancing effect on the endocrine system support overall hormonal balance, stress and immune support. Helps to balance blood sugar levels. Supports both the male and female reproductive system.
Schisandra fruit and seed (Schisandra chinensis): Supportive and protective of liver health. Shown to support immunity, endocrine and nervous system function. Studies have shown may increase in sperm count. Aids stress related infertility.
Shatavari root (Asparagus racemosus): Shatavari’s main constituents are steroidal-saponins, suggesting its use as an estrogen regulator, the estrogen modulating in turn may contribute to menstrual cycle regulation. Not only does this herb support healthy fertility for both women and men, it is an immune system and nutritive tonic. Shatavari supports overall immune system function.
Shiitake mushroom (Lentinula edodes): Stimulates and supports the immune system.
Liver Supporting Herbs
The liver is our chemical processing plant. You can imagine what must go on in there. The liver removes hormones, drugs, and other biologically active molecules from the blood. If there are too many excess toxins and hormones overwhelming the liver, they may be stored up, not only in the liver, but other parts of our body. This can cause or contribute to hormonal imbalances.
- Burdock root (Arctium lappa): Nourishing and cleansing for the liver, aiding in hormonal balance.
Dandelion leaf (Taraxacum officinale): Nourishing. Used to increase nutrition, supportive of liver health, for hormonal balance.
Dandelion root (Taraxacum officinale): Aids in liver health, stimulates digestion for improved hormonal balance.
Milk Thistle seed (Silybum marianum): Milk thistle seed supports hormonal balance through gentle liver cleansing and regeneration. Liver health is vital for hormonal balance. The liver helps to filter toxins from the body, including excess hormones.
Yellow Dock root (Rumex crispus): Stimulates bile production for healthy removal of toxins, supportive of liver health.
Other Herbs to Consider
- Flax seed (Linum usitatissimum): Flax seeds contain lignans, which are the second strongest group of phytoestrogens. Flax is also high in fiber. Studies have shown that these the combination of the lignans and fiber in flax help to remove excess estrogen from the body, while also protecting it from xenoestrogens.
Nettles leaf, root, seed (Urtica dioica): Nutritive; high mineral, vitamin and chlorophyll content. Supportive of gentle cleansing of the liver, lungs, intestines and kidneys. Great adrenal support.
Oatstraw (stems), Milky Oats (tops) exert a stronger effect than oatstraw, (Avena sativa): Nourishing, aids in stress reduction by supporting nervous system. Great support for stress related fertility issues.
Red Clover aerial parts, blossom (Trifolium pratense): Red Clover is a nourishing food herb. It is rich in a variety of vitamins and minerals. It is one of the best blood purifying herbs, aiding in detoxification of environmental pollutants prior to conception. Rich in phytoestrogens, may help protect body from xenohormones.
Seaweed, leafy parts, variety of species: Seaweed is high in fiber which helps improve estrogen metabolism.
Sesame seed (Sesamum indicum): Has the highest oil content of any seed, providing a rich source of omega 3 and 6 EFA’s (see the benefits for hormonal balance above, under Evening Primrose Oil). Contains lignans which help promote healthy estrogen balance and hormonal balance.
Fem Rebalance herbal blend for women combines herbs supportive for restoring hormonal imbalance. This blend is especially helpful after a detox protocol or any other hormonal disruption. Fem Rebalance can help the body’s natural ability to restore normal hormone balance after discontinuing oral contraceptives, during stress or after weight loss.* Learn more here…
Male Performance is blend of adaptogen, libido and male reproductive system supporting herbs. This blend is a first line of defense for aiding men in restoring hormonal balance for improved reproductive health.
To access information on these herbs in more detail, with links to articles on many of the above herbs, please view our Fertility Herbs A-Z Guide here…
Confirmed Hormonal Imbalance
What should you do if you have had your hormones tested and you know specific hormone levels are not where they should be? First talk to your doctor about medical options. For example, if you know you have high thyroid stimulating hormone (TSH), which is confirmation of hypothyroidism, medication is the best option for balancing that particular hormone level. If you know you have low progesterone, your doctor may recommend synthetic progesterone supplementation, but there is a natural safer option with natural progesterone cream supplementation.
We have many articles to help you out. If you know you have a specific hormone level that is not at the correct levels it should be, please choose from one of the articles below to learn more. If you don’t see an article related to an issue you have, you can contact us for more information. Each of the articles we do have provide information on specific diet, supplement, herbal and other natural therapies specific to aiding that hormonal imbalance.
Articles you may find helpful:
Progesterone Fertility Guide
Estrogen Fertility Guide
FSH Levels and Your Fertility
DHEA and Your Natural Fertility
Is My Adrenal Health Affecting My Fertility?
Solve Thyroid Problems Before Conceiving a Baby
Endocrinology and Fertility: The Endocrine System is Vital for Reproductive Health
The endocrine system and the hormones they produce and secrete play a significant role not only in the health of our entire body, but the ability to achieve and sustain pregnancy. Our reproductive system relies on proper hormonal balance to function properly. If you suspect you have a hormonal imbalance get tested. Once you know your test results you will be able to discuss with your doctor the best options for restoring hormonal balance medically. There are natural therapies that can help to restore hormonal balance. Eating a nutrient dense, whole food fertility diet, including daily exercise, stress management techniques and avoiding harmful substances are the foundation for maintaining and restoring hormonal balance. Herbs and nutritional supplements also play a key role in supporting hormonal balance. Herbs for cleansing, liver support and endocrine system support should be considered. Supplements to support optimum nutritional levels may be necessary.
6. Lee, John R., MD, Hopkins, Virginia. Dr. John Lee’s Hormone Balance Made Simple. Grand Central Life & Style, 2006
7. Romm, Aviva. Botanical Medicine for Women’s Health. Churchill Livingstone, 2010
8. Hoffman, David, FNIMH, AHG. Medical Herbalism The Science and Practice of Herbal Medicine. Healing Arts Press, 2003