Androstenes are naturally occurring steroid compounds, part of a broader class known as 16-androstenes, derived from the androstane structure. Found across different species, they influence biological processes and are often associated with chemical communication. These compounds have garnered scientific interest due to their potential roles in physiological and behavioral responses in mammals, including humans.
Types of Androstenes and Their Natural Presence
Several distinct androstenes are recognized, each with unique characteristics and natural origins. Androstenone is a prominent 16-androstene steroid found in high concentrations in boar saliva, and it has also been identified in celery cytoplasm and truffle fungus. This compound is synthesized from androstadienone and can be further converted into other forms.
Androstenol is another significant 16-androstene, characterized by a musk-like odor. It is present in human urine, blood plasma, saliva, and axillary sweat. In both humans and boars, androstenol is biosynthesized in the testes, and it can also be produced in the adrenal glands and ovaries in humans.
Androstadienone is a related compound found in human axillary secretions. These compounds, including androstenone and androstenol, are unsaturated C-19 steroids. Their presence in bodily fluids like sweat and urine suggests a role in biological signaling, although their full natural functions in humans continue to be investigated.
Androstenes and Human Social Cues
The proposed role of androstenes as human pheromones has been a subject of scientific inquiry. Pheromones are chemical signals that, in animals, typically elicit specific behavioral or physiological responses from other members of the same species. Androstenone and related 16-androstenes are among the most studied compounds for their potential communicative roles in humans.
Research suggests that androstenes may influence human mood, social perception, and attraction, although findings are often inconsistent. For instance, some studies indicate that exposure to androstenol can make social partners appear more appealing or approachable, and it has been reported to affect mood states. However, other research has yielded mixed or minimal effects, with some studies finding no impact on attractiveness ratings or unfaithfulness judgments.
The concept of human pheromones is complex partly because humans possess a vomeronasal organ, which detects pheromones in many mammals, but its function in adult humans is not clearly established. A fraction of the human population experiences specific anosmia, an inability to detect the odor of androstenone, which can vary from an unpleasant urine-like smell to a pleasant sweet or floral scent. While some studies have shown that individuals initially unable to smell androstenone can acquire sensitivity through repeated exposure, the overall scientific consensus on androstenes acting as human pheromones remains debated, with little robust evidence for consistent sex-attractant effects.
Commercial Applications and Considerations
Androstenes are commercially available, primarily in the form of pheromone sprays and, less frequently, in certain supplements. Manufacturers of these products often claim that androstenes can enhance self-confidence, improve social interactions, or increase sexual attractiveness. However, scientific evidence supporting these broad claims is limited and often inconsistent, leading to skepticism within the scientific community.
It is important to distinguish androstenes from anabolic steroids. Anabolic steroids (AAS) are structurally related to testosterone and are primarily used to increase muscle size, strength, and athletic performance by binding to androgen receptors. Examples include testosterone and its synthetic derivatives. Androstenes, while also steroids, do not possess the same anabolic properties as AAS and are not used for muscle building.
Androstenedione, a different steroid sometimes referred to as “andro,” is a precursor to testosterone and estrogen and has been marketed as a supplement to boost testosterone levels. While it is also a steroid and has been associated with performance enhancement, it is distinct from the 16-androstenes like androstenone and androstenol. Its efficacy for increasing strength or lean body mass is not fully proven. The use of such supplements, including androstenedione, is banned by major sporting bodies like the World Anti-Doping Agency due to concerns over performance enhancement and potential health risks. Commercial products containing androstenes are largely unregulated, and their long-term health effects or efficacy are not well-established. Consumers should consider the lack of scientific consensus on their purported benefits.