What is the Difference Between Estrogen and Progestin

The main difference between estrogen and progestin is that the estrogen is the primary female sex hormone whereas the progestin is a pill with a combination of both estrogen and progesterone. 

Estrogen and progestin are two types of sex hormones that can be taken in the form of pills. Furthermore, estrogen is responsible for the development of secondary sexual characteristics in females while progestin prevents ovulation during the menstrual cycle.

Key Areas Covered

1. What is Estrogen
     – Definition, Features, Importance
2. What is Progestin
     – Definition, Features, Importance
3. What are the Similarities Between Estrogen and Progestin
     – Outline of Common Features
4. What is the Difference Between Estrogen and Progestin
     – Comparison of Key Differences

Key Terms

Birth Control Pills, Estrogen, FSH, LH, Progesterone, Progestin, Secondary Sexual Characteristics

What is Estrogen

Estrogen is the primary sex hormone in females. It is a steroid hormone. Actually, the term estrogen covers a group of hormones, including estrone, estradiol, and estriol. The synthesis of estrogens occurs in the ovaries, the grape-sized glands located on either side of the uterus. Moreover,  the fat cells in the adrenal gland produce a small amount of estrogen. In addition, follicle stimulating hormone (FSH) regulates the synthesis of estrogens.

Figure 1: Estradiol

Moreover, the main function of estrogens is the development of the secondary sex characteristics in females, including the enlargement of the breast, thigh muscles, and hip, development of armpit hair and pubic hair, and deposition of subcutaneous fat and fat deposits. Furthermore, low levels of estrogen may lead to less frequent menstrual cycles, dryness and thinning of the vagina, mood swing, etc. Besides, higher levels of estrogen may lead to heavy bleeding during the menstrual cycle, fatigue, weight gain, and fibrocystic breasts. Generally, the levels of estrogens increase at the middle of the menstrual cycle, at the point of ovulation. Estrogens are also produced artificially for use in oral contraceptives or to treat menopausal and menstrual disorders.

What is Progestin

Progestin is a pill which comes in a combination of estrogen and progesterone together. The main function of progestin is to prevent the release of eggs at the middle of the menstrual cycle, which in turn prevents pregnancy. Herein, the primary function of estrogen in the pill is to prevent the synthesis of FSH and LH in the pituitary gland. Also, it prevents the mid-cycle breakthrough bleeding. On the other hand, progesterone is responsible for preventing the synthesis of LH, which in turn prevent the release of the egg. Also, it increases the thickness of the uterine lining to prevent the implantation of the egg. It reduces the ability of the egg fertilized by sperms. Progesterone thickens the cervical mucus to hinder the ability of sperms to travel into the uterus as well.

Figure 2: Progesterone

Progestin is more effective than progesterone-only birth control pills. But, some patients have allergies in response to synthetic estrogens in the progestin pills. There, progesterone-only birth control pills are effective.

Similarities Between Estrogen and Progestin

• Estrogen and progestin are two types of sex hormones.
• Both can be used as birth control pills.

Difference Between Estrogen and Progestin

Definition

Estrogen refers to any of a group of steroid hormones which promote the development and maintenance of female characteristics of the body while progestin refers to a natural or synthetic steroid hormone which maintains pregnancy and prevents further ovulation during pregnancy. Thus, this explains the main difference between estrogen and progestin.

Significance

Another difference between estrogen and progestin is that the three types of estrogen hormones are estrone, estradiol, and estriol while the progestin contains both estrogen and progesterone.

Synthetic/Natural

Estrogen is a natural hormone while progestin is a combination of synthetic hormones. This is a major difference between estrogen and progestin.

Importance

Also, the estrogen is responsible for the development of secondary sexual characteristics of females while progestin is a type of birth-control pill which mainly prevents the release of eggs.

Conclusion

Estrogen is the female sex hormone which is responsible for the development of secondary sexual characteristics in females. The three types of estrogens are estrone, estradiol, and estriol. On the other hand, progestin is a synthetic hormone combination, which contains both estrogen and progesterone. It can prevent the release of eggs, which in turn prevent the pregnancy. Therefore, the main difference between estrogen and progestin is their function.

Reference:

1. Bradford, Alina. “What Is Estrogen?” LiveScience, Purch, 2 May 2017, Available Here
2. “Estrogen Vs. Non-Estrogen Birth Control Pills – What’s the Difference?” PRJKT RUBY, 12 Nov. 2015, Available Here

Image Courtesy:

1. “Estradiol” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia  
2. “Progesterone-2D-skeletal” (Public Domain) via Commons Wikimedia