Saw Palmetto: What It Is, Properties, Benefits and How to Take It

Saw Palmetto: What It Is, Properties, Benefits and How to Take It

Saw Palmetto is a supplement with potentially beneficial properties for human health: such as reducing symptoms of benign prostatic hyperplasia and preventing hair loss.

What is Saw Palmetto and how is it obtained?

Saw Palmetto is a supplement that’s produced from the fruits of the Serenoa Repens plant

It’s an oily compound formed by a great variety of bioactive substances, including esterified fatty acids (triglycerides, mainly) and free fatty acids (oleic, lauric and myristic fatty acids); phytosterols, flavonoids, polysaccharides and amphipathic alcohols.

With this composition, it’s normal for you to have doubts. Okay, Saw Palmetto works, but which of all these substances in it are the ones that exert the positive effects we’re looking for?

The truth is that the active ingredients of Saw Palmetto, as well as its mechanism of action, are not fully known, as they don’t really act in a single way.

To clarify this, which was completely unknown until about a decade ago, Masayuki et al. (2009) isolated the principles found in a Saw Palmetto supplement to see which of them presented the mechanism of action that makes Saw Palmetto such an effective product for the treatment of the aforementioned pathologies.

And they discovered that the oleic acid found in the supplement was the substance that principally produced the desired effects; lauric and myristic fatty acids also shared the same mechanisms, but their affinity was less.

Among the properties of this active ingredient has is that of being a potential treatment for prostate health

What is Benign Prostate Hyperplasia?

Benign prostate hypertrophy (hyperplasia) (BPH) is one of the most common potentially pathologic conditions in middle- and older-aged men

It’s one of the main causes of development of lower urinary tract symptoms (LUTs), such as:

  • Incomplete emptying of the bladder
  • Elevated urinary frequency
  • Intermittence in the process
  • Sudden urge to urinate
  • Low pressure in urination
  • Requirement of high efforts to initiate and maintain urination
  • Nocturia

Why does this happen?

Benign prostate hyperplasia is influenced by a large number of factors that condition the prevalence of the disease, from age, race, genetic factors that predispose to the growth and proliferation of prostate cells, to environmental factors.

In turn, there is a direct correlation between BPH-Metabolic Syndrome-LUTs-Erectile Dysfunction. Making those who suffer from obesity or being overweight, diabetes and alterations in glucose metabolism, and dyslipidemia, may suffer from these pathological conditions.

Benign Prostatic Hyperplasia BPH

Figure I. Graphic representation of the anatomical structure of the urogenital system with a normotrophic prostate and BPH. Source:

What are the symptoms of an inflamed prostate?

When the prostate increases in size, it compresses the intersection between the bladder and the urethra, reducing the diameter of the duct lumen, making it difficult for urine to pass, making a complete emptying of the bladder difficult, requiring effort and generating the need to urinate frequently due to not being emptied

In addition, despite the extensively established correlation in literature between BPH and erectile dysfunction, the mechanisms by which BPH can affect penile erectile capacity have not been unanimously established.

Although it is hypothesised that it is due to endothelial dysfunctions related to an alteration in the activity of nitric oxide synthase (enzyme responsible for producing nitric oxide that relaxes the walls of the blood vessels allowing greater blood flow) and/or partial ischemia of the penis

At what age does it occur?

If we combine all this and mix it, in the end we obtain epidemiological statistics on BPH that show an increase in the development of the condition from the age of 40, presenting a prevalence between 8-60% in elderly adults (Lim, 2017)

Incredible as it may seem, there is a compound capable of acting in all ways that interrelate these 4 processes: BPH, LUTs, erectile dysfunction and age-related alopecia.

This complex picture is closely linked to alopecia in men. If you want to know more about this pathology, click Alopecia, How do you treat it?

Saw Palmetto on the pathophysiology of BPH and LUTs?

There are 2 great mechanisms that condition the appearance of BPH and therefore LUTs

First of all, the concentrations of dihydrotestosterone in males (it’s also the mechanism directly linked to alopecia), which is also the main trigger for BPH.

Secondly, all the mechanisms related to the contraction of prostate tissue, which consists of the continuous overactivation of the prostate through mechanisms dependent on the release of calcium that generate a narrowing of the urethra duct by compression when the contracted prostate tissue is found.

These mechanisms are most related to LUTs and usually become visible when we suffer from BPH


Dihydrotestosterone (DHT) is the reduced form of testosterone

This is produced by a conversion process mediated by two isoenzymes called 5-alpha-reductase type 1 and type 2. Both act the same, but the distribution in the tissues is different; with those of type 2 predominating in the prostate and the hair follicle of the scalp; and we also have type 3, but its influence on these aspects is less.

The DHT that is generated in the prostate binds to the androgenic receptor of the smooth cells present in the tissue, leading to a whole process of transcription and translation of the genetic code that leads to cell proliferation (hyperplasia) and therefore enlargement of the prostate.

Genomic signalling

Figure II. Genomic signalling by which DHT agonises the androgenic receptor (AR) and initiates the process of genetic transcription leading to cell proliferation. (Liao et al. 2013)

And be careful, because hyperactivating genetic transcription is a delicate process, because if a mutation is generated in one of the DNA replications that for some reason “survives” and is able to leave the control of normal cell proliferation… we’re going to be looking at prostate cancer

The traditional treatment to avoid this cell proliferation is the reversible inhibition of the action of the enzyme 5-alpha-reductase in those who for some reason have a mutated genotype that overactivates this enzyme; finasteride or duasteride will sound familiar to many people, as they’re drugs that inhibit the action of different isoenzymes.

Saw Palmetto acts in the same way as duasteride, inhibiting both types of reducing isoenzymes, which is extremely effective in inhibiting reductase activity.

Saw Palmetto on 5-alpha-reductase enzyme inhibition

Figure III. Graphic representation of the effects of Saw Palmetto extract on the inhibition of the enzyme 5-alpha-reductase, the inhibition of its coupling to the androgen receptor and the anti-inflammatory and apoptotic effects on prostate tissue smooth cells by this (Suzuki et al. 2009)

Here we can see that the treatment with Saw Palmetto, at a concentration of 3.58mcg/ml, inhibits half the activity of the enzyme; at a concentration of 10mcg/ml, the inhibition is 90%.

5-alpha reductase enzyme inhibition

Figure IV. Percent inhibition of the enzyme 5-alpha reductase (Mean Inhibition (%)) based on the concentration of Saw Palmetto in the medium (Concentration (mcg/mL) in vitro (Pais, Villar & Rull., 2016)

In turn, the activity of the DHT on the hair follicle begins a sequence of reactions that result in calcification and fibrosis of the follicle that produce a lower contribution of oxygen and a hypoplasia of the scalp from the base (thinner hair that’s susceptible to damage and falling out)

Calcium-dependent mechanisms

To avoid making the article longer than necessary, Saw Palmetto lipoesterols act on the inhibition of tissue muscarinic receptors, inhibiting alpha-1 adrenergic receptors present in the prostate and blocking 1,4-dihydropyridine receptors in prostate tissue cells.

Explaining each mechanism individually is a long and complex process, but what’s important to understand is that:

  • Alpha-1 adrenergic receptors respond to catecholamines (adrenaline and norepinephrine)
  • Muscarinic receptors respond to acetylcholine
  • 1,4-dihydropyridine receptors respond to pyridine
When we say that they “respond”, what we are reffing to is when their neurotransmitter (activator) binds to the receptor – it activates it and all of them generate a sequence of responses that end up producing the output of calcium from the sarcoplasmic reticulum (where the cells store calcium), it binds to calmodulin, a protein that binds to calcium forms the Ca++/CM complex that phosphorylates MLCK, and it binds to actin and produces contraction

It is more or less similar to the process by which a bicep contracts, although slightly different as the prostate tissue is smooth muscle and not striated; that contraction narrows the transit area of the urethra through the prostate and hinders the urination process.

Molecular signalling

Figure V. Molecular signalling pathway leading to muscle contraction. Source:

Saw palmetto and Tamsulosin

For example, Tamsulosin, which is one of the most prescribed drugs to cope with LUTs produced by BPH, is based on the antagonisation of alpha-1 adrenergic receptors to prevent involuntary contraction of prostate tissue; just as Saw Palmetto acts.

Saw palmetto and Erections

Finally, and although this is anecdotal, Saw Palmetto has been used for decades as an aphrodisiac and invigorator, and this is because it shares the same mechanism of action as drugs such as Sidenafil (Viagra, Kamagra…) and is its inhibitory activity on PDE5

Smooth muscle

Figure VI. Regulation of smooth muscle, phosphodiesterase 5 (PDE5) and its effects on the inhibition of muscle relaxation. (Cobin, 2004)

PDE5 (phosphodiesterase 5) is an isoenzyme of the phosphodiesterase superfamily that is expressed in tissues such as the brain, lungs, or bladder and smooth muscle.

PDE5 is an enzyme that degrades cGMP (cyclic guanosine monophosphate), which acts as a messenger when nitric oxide reaches muscle tissue.

If we inhibit this enzyme, the concentration of cGMP increases in the cell, and eventually it activates PKG (Protein Kinase G), which is responsible for initiating a cascade of reactions that cause calcium to enter the sarcoplasmic reticulum and, therefore, relax the muscle tissue of the cavernous body of the penis and increase its erectile activity

Saw palmetto Daily dose

Yang et al. (2013) showed how Saw Palmetto extract decreased PDE5 activity in a dose-dependent manner , reaching its maximum inhibition at 5.716mg/kg.

Activity of PDE5

Figure VII. PDE5 activity as a function of the dose of Saw Palmetto extract (SPE) in rats. (Yang et al., 2013)

Remember that these doses are not extrapolable to humans and in no case should you exceed 320mg of Saw Palmetto Extract with a fatty acid content of 80-90%

Saw Palmetto extract showed a greater amplitude (erectile activity) in a dose-dependent manner; like sidenafil; its magnitude came to be equated with that of sidenafil at its highest doses.


Figure VIII. Comparison between penile erectile response following administration of electrical stimulation following administration of different doses of sidenafil (A) and Saw Palmetto extract (B) in rats. (Yang et al., 2013)

Buy Saw palmetto

Buy Saw Palmetto Supplements at the best price possible with HSN

You can buy Saw Palmetto Extract from the EssentialSeries brand that is Vegan-Friendly, Gluten-Free, Lactose-Free, Fish-Free, Non-GMO, and contains No Nuts

Saw Palmentto by HSN

EssentialSeries Saw Palmetto.

Each veg pearl (one of the few manufacturers that offers a softgel of non-animal origin) provides:

  • 320mg of Saw Palmetto Oil
  • 80mg of Pumpkin Seed Oil

Forming an excellent formula for human health, with 85% unsaturated fatty acids, which, as we have seen, and according to research: oleic acid and lauric acid inhibited 5a-reductase.

Combining Saw Palmetto with a nitric oxide precursor such as Citrulline Malate can be an effective alternative therapy to improve male sexual activity.

Bibliographic Sources

  1. Corbin, J. D. (2004). Mechanisms of action of PDE5 inhibition in erectile dysfunction. International Journal of Impotence Research, 16 Suppl 1, S4-7.
  2. Liao, R. S., Ma, S., Miao, L., Li, R., Yin, Y., & Raj, G. V. (2013). Androgen receptor-mediated non-genomic regulation of prostate cancer cell proliferation. Translational Andrology and Urology, 2(3), 187–196.
  3. Pais, P., Villar, A., & Rull, S. (2016). Determination of the potency of a novel saw palmetto supercritical CO2 extract (SPSE) for 5α-reductase isoform II inhibition using a cell-free in vitro test system. Research and Reports in Urology, 8, 41–49.
  4. Suzuki, M., Ito, Y., Fujino, T., Abe, M., Umegaki, K., Onoue, S., … Yamada, S. (2009). Pharmacological effects of saw palmetto extract in the lower urinary tract. Acta Pharmacologica Sinica, 30(3), 227–281.
  5. Yang, S., Chen, C., Li, Y., Ren, Z., Zhang, Y., Wu, G., … Yao, M. (2013). Saw palmetto extract enhances erectile responses by inhibition of phosphodiesterase 5 activity and increase in inducible nitric oxide synthase messenger ribonucleic acid expression in rat and rabbit corpus cavernosum. Urology, 81(6), 1380.e7-13.

Related Entries on the subject:

  • Foods that increase Testosterone
  • Supplements to Increase Muscle Mass
  • Learn about the benefits of campesteroles
  • Exercise is important at any time of life, and although sometimes we want to believe that it’s not, it’s also important for older people. Read More
Review of Saw Palmetto

Natural treatment against BPH - 92%

Improvement of capillary growth - 94%

Improvement of sexual relations - 92%

Improvement of mood - 94%

Reducing of urination problems - 95%


HSN Evaluation: 4.7 /5
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About Melanie Ramos
Melanie Ramos
Melanie Ramos uses the HSN Blog to share the latest information and content, so that all those readers who want to learn.
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