What is the Difference Between Estrogen and Phytoestrogen

The main difference between estrogen and phytoestrogen is that estrogen is a steroid hormone that regulates the secondary female sexual characteristics, whereas phytoestrogen is a plant-based hormone that functions similarly to animal estrogen. 

Estrogen and phytoestrogen are two hormones that control secondary female sexual characteristics.    

Key Areas Covered

1. What is Estrogen
– Definition, Facts, Features
2. What is Phytoestrogen
– Definition, Facts, Features
3. Similarities Between Estrogen and Phytoestrogen
– Outline of Common Features
4. Difference Between Estrogen and Phytoestrogen
– Comparison of Key Differences
5. FAQ – Estrogen and Phytoestrogen
– Answers to frequently asked questions

Key Terms  

Estrogen, Phytoestrogen

Difference Between Estrogen and Phytoestrogen - Comparison Summary

What is Estrogen

Estrogen is the primary female sex hormone. Similar to androgens in males, in females, estrogen is responsible for the development of the female reproductive system and the secondary female sex characteristics at puberty.

The secondary female sex characteristics include:

  • The development of breasts.
  • The widening of the hips.
  • The distribution of fat in the body.
Compare Estrogen and Phytoestrogen

Figure 1: Estrogen Types 

After puberty, estrogens are responsible for the regulation of the menstrual cycle.

Moreover, the luteinizing hormone (LH) and the follicle-stimulating hormone (FSH) are the two hormones responsible for regulating the production and release of estrogens. Besides, three types of estrogen hormones occur in the female body in higher amounts. They are estrone, estradiol, and estriol. Out of these three, estradiol is the most potent form of estrogen.

What is Phytoestrogen

Phytoestrogen is a non-steroid estrogen with a plant origin. Structure-wise and function-wise, it is similar to endogenous estradiol. Isoflavones such as daidzein and genistein are the major class of phytoestrogen. The other most frequent phytoestrogen type is lignin, such as enterodiol and enterolactone. Functionally, phytoestrogens bind to the estrogen receptor, activating it. They are structurally similar to the endogenous 17β-estradiol. Therefore, they give an equal strength to the endogenous 17β-estradiol. However, the binding of phytoestrogen is weak. Also, in the presence of a high endogenous amount of estrogen, phytoestrogen shows an antiestrogenic effect due to its weak binding. It prevents the binding of endogenous estrogen to the receptor.

Estrogen vs Phytoestrogen

Figure 2: Phytoestrogen Types 

Furthermore, the richest dietary source of isoflavones is soy. Also, the primary dietary source of lignin is flax. The other types of phytoestrogens include flavonoids and coumestans. Meanwhile, flavonoids occur in several edible plants. Also, alfalfa sprouts are a source of coumestans. 

Similarities Between Estrogen and Phytoestrogen

  • Estrogen and phytoestrogen are two hormones that are similar in function.
  • They contain aromatic rings.
  • They bind to the receptors to activate a function.  

Difference Between Estrogen and Phytoestrogen


Estrogen refers to any group of steroid hormones that promote the development and maintenance of female characteristics of the body. In contrast, phytoestrogen refers to a substance found in certain plants that can produce effects like that of the hormone estrogen when ingested into the body.


Estrogen is the hormone that regulates the secondary female characteristics, while phytoestrogen is a plant-based hormone that functions similarly to animal estrogen. 


Estrogen is a steroid hormone, while phytoestrogen is not a steroid hormone. 


The three types of estrogen include estradiol, estrone, and estriol, while the most common type of phytoestrogen in plants is isoflavones.

FAQ: Estrogen and Phytoestrogen

Do phytoestrogens increase estrogen levels in men? 

Phytoestrogens in soy can reduce testosterone levels in men. But they do not affect the luteinizing hormone. Meanwhile, they can increase estrogen levels in men, decreasing testosterone levels.

What is another name for phytoestrogens? 

Isoflavones, daidzein, genistein, ipriflavone, ostivone, and soy isoflavones are other names for phytoestrogens.  

Do phytoestrogens increase estrogen? 

Phytoestrogen has both estrogenic and antiestrogenic effects. Therefore, some phytoestrogens have estrogen-like effects and increase estrogen levels in the body. Other phytoestrogens block the estrogen hormone, producing antiestrogenic effects. 


In brief, estrogen and phytoestrogen are two hormones that have similar functions. Estrogen is the hormone in females that regulates secondary sexual characteristics. Also, it is a steroid hormone. The three types of estrogens are estradiol, estrone, and estriol. In contrast, phytoestrogen is a plant-based hormone that functions similarly to animal estrogen. However, it is not a steroid hormone. The primary type of phytoestrogen is isoflavonoids. Therefore, the main difference between estrogen and phytoestrogen is their types.           

  1. Delgado BJ, Lopez-Ojeda W. Estrogen. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
  2. Phytoestrogen. Phytoestrogen – an overview | ScienceDirect Topics. (n.d.).
Image Courtesy:
  1. Estrogen” By Pamela Frank – Own Work (CC BY SA 4.0) via Commons Wikimedia
  2. Phytoestrogens2” By Boghog2 – Own Work (Public Domain) via Commons Wikimedia

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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