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Writer's pictureMeredith Paci

What is the difference between bioidentical progesterone vs a progestin anyway?

Updated: Sep 21, 2024

Progestogens is defined as a type of medication or agent “which produces effects similar to those of the natural female sex hormone progesterone in the body” (source). Understanding we are not speaking of naturally produced progesterone by the ovaries (brain or adrenal glands). Progestogens comprise two primary types of medications: progesterone, sourced primarily from plants and occasionally from animal origins (pretty rare), and progestins, synthetic compounds that, surprisingly, also find their roots in plant sources. Something worth mentioning is depending what country you are in as well as what literature you are reading progestogen can mean either a bioidentical progesterone or a progestin. It is a blanket tem that you must ensure you get defined as even though both fall under the category of ‘similar to those of natural progesterone’ you will come to see how different they are. Which brings us to a very important point. 


This may offend some:


We believe it is crucial to recognize that the synthetic nature of progestins alone doesn't inherently denote superiority or inferiority; rather, it reflects their origin and subsequent modification. Common apprehension to synthetic anything often surrounds terms like "derived in a lab," yet it's important to acknowledge that that specific apprehension is a bit misplaced as many medications, including those labeled natural and bioidentical, are derived from a lab setting and undergo laboratory refinement. It's also noteworthy that progestins' chemical structures are inspired by compounds present in plants, much like those from which progesterone originates. 


Consequently, the notion of "natural" shouldn't be automatically equated with superiority; many natural substances carry significant risks. We believe context matters tremendously as each client whom we work with should not be made to feel because the option that is best for her/his health situation is synthetic, that it is of less quality or they in some way are doomed. Instead, the safety and effectiveness of progestogens, whether natural or synthetic, hinge on individual circumstances and health considerations, emphasizing the importance of context in evaluating their use. 


Now let’s discuss what is the difference between a bioidentical progesterone vs a progestin!


Bioidentical Progesterone:


Bioidentical progesterone, as the name suggests, is structurally as close to being identical to progesterone naturally produced by the ovaries as possible. Derived primarily from plant sources such as wild yams or soybeans. This similar resemblance to endogenous progesterone allows bioidentical progesterone to interact with progesterone receptors in the body in a manner akin to the body's own hormone, exerting similar biological effects.



Progestins: 


In contrast to bioidentical progesterone, progestins are synthetic compounds (also starting from plant sources) designed to mimic the actions of progesterone. Progestins can be derived from various starting materials, including progesterone and testosterone. The process of synthesizing progestins involves chemical modifications to these precursor molecules to create compounds with specific hormonal activities and properties. Although structurally similar to progesterone, because of these variations in their chemical structures can lead to differences in their biological activities and metabolic pathways compared to natural progesterone.

Similarities and differences:



Bioidentical progesterone serves to supplement the body's natural progesterone levels, with its application varying depending on the individual's needs. This can include supporting fertility, managing conditions like endometriosis or adenomyosis, or addressing symptoms associated with perimenopause and menopause. It's crucial to recognize that progesterone's primary role is linked to fertility, even if pregnancy isn't the immediate goal. Consequently, fertility specialists typically opt for bioidentical progesterone over progestins when assisting individuals trying to conceive, acknowledging the nuanced role of progesterone in fertility support.

However, it's essential to understand that bioidentical progesterone usage in very late perimenopause or with someone post-menopausal won't stimulate ovulation or reinstate fertility. Instead, it aims to complement the body's dwindling progesterone production during this stage. Nonetheless, it's worth noting that pregnancy remains a possibility for individuals who still are ovulating during perimenopause with or without the addition of bioidentical progesterone. 

On the other hand, progestins function differently; they inhibit ovulation and deter the body from initiating the reproductive processes associated with fertility. While certain progestin-based contraceptives may theoretically permit ovulation, some formulations act to suppress the brain-ovary axis entirely. It has been suggested that progestin’s support hormone health and do not change this brain-ovary communication. This bears to question, if the goal is to support hormone health by supporting progesterone, then why would fertility specialists opt for bioidentical progesterone over progestins? Do you see the conundrum?

Despite these differences, both progestins and bioidentical progesterones hold significant therapeutic value. We understand that and why we want to ensure we open dialogues as opposed to shut them down. We are pro informed decision making!



Risk, Reward and Rational Assessment 


In navigating healthcare decisions, it's essential to conduct a comprehensive risk, reward, and rational assessment. This approach not only ensures informed decision-making but also emphasizes the importance of ongoing follow-up and dialogue with healthcare providers. As health coaches, we play a crucial role in supporting our clients by facilitating discussions and encouraging active engagement with their healthcare providers.

A prime example of the need for follow-up is evident in the guidelines for the Mirena IUD, which recommend regular re-examinations and evaluations following insertion. According to the manufacturer's guidelines, it states, “Reexamine and evaluate patients 4 to 12 weeks after insertion and once a year thereafter, or more frequently if clinically indicated.” However, it's surprising how often clients reveal they haven't seen their doctor since the insertion, sometimes spanning over two years. This oversight underscores the importance of routine healthcare follow-up and the potential consequences of neglecting such recommendations.

Moreover, depth in follow-up is often lacking, with surface-level inquiries failing to uncover potential issues beyond the surface (ie: “Are you having a period?”) .


Progestin-based interventions, for instance, have been associated with various changes, that warrant follow up including:

  • Mood alterations, including depression and anxiety

  • Changes in body composition

  • Changes in glucose tolerance/insulin sensitivity

  • Acne and skin rashes

  • Micronutrient deficiencies


While bioidentical progesterone isn't exempt from potential effects, its role in supporting or augmenting natural progesterone production often confers a supportive and protective function when appropriate. 


Bioidentical progesterone may offer potential protective and beneficial effects such as:

  • Protective of Endometrial cancer

  • Protective of Breast cancer 

  • Risk reduction in congestive heart failure (as supported by new studies)

  • Improved sleep

  • Promotion of scalp hair growth/regrowth

  • Enhancement of bone health

  • Brain benefits (neurosteroid)


However, it's crucial to acknowledge that the protective nature of hormone interventions can vary with age and individual health status. Recent research suggests potential benefits of progestin therapy in combination with estrogen therapy for breast cancer protection in individuals over 65, highlighting the evolving landscape of hormone therapy recommendations.


Ultimately, any intervention, whether bioidentical progesterone or progestin-based, should be carefully discussed with a healthcare provider, ideally in collaboration with a health coach. By fostering a collaborative approach, we can ensure comprehensive support for our clients, addressing both immediate needs and long-term considerations.

The choice between bioidentical progesterone and progestins hinges on individual factors. What may be suitable for one individual may not necessarily be the best option for another. Therefore, tailoring recommendations based on individual needs and circumstances is paramount.


As a final note: 


Did you know that bioidentical progesterone does not only come compounded? We find that many individuals assume bioidentical means compounded. Not the case. Perhaps another blog at a later date on this. We recognize this blog is only the tip of the discussion but we hope it sparks curiosity.


If you know a female, sharing is caring! We encourage you to share our blogs with others and on your social media. Let’s start unlocking the dialogue and empowering each other.  If you are wanting 1 on 1 support via a consultation or coaching please reach out below. 




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