Wirkung und Nebenwirkungen der Sägepalme – bringt die Anwendung tatsächlich Vorteile für die Haare?

*Serenoa repens*, commonly referred to as saw palmetto or sabal palm, is a perennial plant species indigenous to the southeastern regions of North America, select areas of Southern Europe and Northern Africa, as well as the Antilles and the Bahamas. It typically grows as a dense shrub reaching heights of 0.6 to 2.1 meters or as a small tree averaging up to 3 meters tall. Notably long-lived, certain specimens have been documented to survive for 500–700 years. Its morphological structure features abbreviated stems crowned by stiff, fan-shaped fronds in shades of green or blue-green, segmented into narrow, ribbon-like leaflets. The common name "saw palmetto" derives from the sharp spines lining the petioles. The plant produces diminutive white flowers that mature into small, glossy fruits—initially green but darkening to near-black as they ripen between October and December. These single-seeded, olive-sized berries contain a spectrum of pharmacologically active compounds, leading to the inclusion of saw palmetto in the 23rd edition of the *United States Pharmacopeia* (USP) during the 20th century. Its chemical composition encompasses phytoestrogens, phytosterols, terpenoids, flavonoids, fatty acids (including oleic, linoleic, and lauric acids), lectins, polysaccharides, and aliphatic alcohols. Lipidosterolic extract analyses have identified the following fatty acid profile: oleic acid (29.8%), linoleic acid (21.5%), lauric acid (16.5%), palmitic acid (9.0%), myristic acid (6.2%), stearic acid (2.6%), linolenic acid (2.3%), caprylic acid (1.4%), capric acid (0.9%), and oleopalmitic acid (0.1%) [1].

Extracts derived from the fruit of Serenoa repens (commonly referred to as saw palmetto or sabal palm) demonstrate a well-documented inhibitory effect on 5α-reductase enzymes (types I and II), thereby substantially reducing the conversion of testosterone into its more potent metabolic derivative, dihydrotestosterone (DHT). This mechanistic pathway underpins the plant’s pronounced anti-androgenic properties, which have been corroborated through extensive in vitro investigations and clinical trials. Preparations containing this botanical extract are widely recommended as adjunctive therapy for benign prostatic hyperplasia (BPH) in its early and moderate stages (Grade I and II), where they contribute to symptom alleviation by suppressing glandular cell proliferation and enhancing lower urinary tract urodynamics.

Pharmacological research indicates that Serenoa repens extends beyond its antiproliferative effects, exhibiting diuretic properties that facilitate the elimination of excess fluids while simultaneously demonstrating antiseptic activity within the urinary tract, thereby mitigating the risk of secondary infections. Furthermore, the active constituents present in these extracts—including flavonoids, high-molecular-weight polysaccharides such as mannitol, phytosterols (primarily β-sitosterol), and medium-chain triglycerides—exert a synergistic anti-inflammatory effect. Consequently, these formulations accelerate the regression of symptoms associated with chronic prostatitis, a condition that also affects younger men (under 35 years of age), although the pathophysiology in this demographic warrants further investigation.

From an andrological perspective, preliminary evidence suggests potential benefits of Serenoa repens in patients with idiopathic male infertility, particularly when infectious factors compromise semen quality. However, due to the limited number of randomized clinical trials, additional well-designed studies are necessary to definitively validate this hypothesis. Additionally, owing to its capacity to modulate androgen levels, this extract has found applications in dermatology—both in the management of androgenetic alopecia (in men and women) and in the treatment of hirsutism, the excessive male-pattern hair growth in women, where it serves as a viable alternative to conventional hormonal therapies.

Extracts derived from *Serenoa repens* (saw palmetto) are widely regarded as having a favorable safety profile and are generally well tolerated by most individuals [1, 4, 6]. Adverse reactions occur infrequently, tend to be mild in nature, and are predominantly confined to gastrointestinal disturbances—including episodes of nausea, vomiting, diarrhea—as well as systemic symptoms such as dizziness and headaches of moderate severity. Prolonged administration may predispose individuals to coagulation disorders, and in isolated instances, it has been associated with the onset of acute pancreatic inflammation [6]. Use during pregnancy is strictly contraindicated due to potential teratogenic effects and the risk of precipitating preterm labor. Additionally, supplementation should be avoided during lactation, concurrent use of hormonal contraceptives, or in the immediate period preceding scheduled surgical interventions.

As substantiated by prior clinical observations and phytotherapeutic research, the fruit extract of saw palmetto (*Serenoa repens*) demonstrates significant efficacy in mitigating the progression of androgenetic alopecia—a condition predominantly affecting men over the age of 40, though it may also manifest in postmenopausal women due to the physiological decline in estrogen levels. The mechanism of action for this botanical extract centers on its capacity to selectively inhibit the enzyme 5-alpha-reductase, thereby reducing concentrations of dihydrotestosterone (DHT)—an androgen metabolite whose excessive activity contributes to follicular miniaturization and accelerated hair shedding. Within the framework of a comprehensive anti-baldness regimen, the systematic application of topical formulations—such as nutrient-rich serums, restorative hair masks, and shampoos fortified with standardized saw palmetto extract—is strongly advised. These products, enriched with bioactive phytosterols and fatty acids, not only decelerate the atrophy of hair follicles but also enhance overall scalp health by regulating sebum production. Notably, both oral supplementation and external application of the extract may serve a prophylactic role in individuals with genetic predispositions or compromised hair integrity. Optimal therapeutic outcomes are achieved through a consistent, minimum three-week application cycle—preferably following thorough hair cleansing to facilitate deeper penetration of active ingredients. It is worth emphasizing that saw palmetto is also employed in alleviating symptoms associated with benign prostatic hyperplasia (BPH), which can substantially improve quality of life for middle-aged and elderly patients. Prior to initiating treatment, particularly in cases involving comorbid urogenital conditions, consultation with a healthcare provider is essential to tailor dosage and avoid potential drug interactions. Preparations containing *Serenoa repens*—whether in the form of serums, shampoos, or dietary supplements—are widely accessible through brick-and-mortar and online pharmacies, specialty drugstores, and health food retailers. Their regular use contributes to visible hair densification, reinforcement of the hair shaft from root to tip, and a marked reduction in daily hair loss, as corroborated by extensive studies and user testimonials.