What “Natural” Actually Means in an Insect Repellent
Many consumers automatically assume that a “natural” insect repellent must be safer than a synthetic alternative – but the current science tends to disagree. Plant-based repellents have been used for generations. They are generally considered safe simply because they have been used historically. As the demand for plant-based products continues to increase, with natural fragrances preferred over synthetic odors, it is becoming increasingly imperative to compare the safety and effectiveness of these “natural” repellents with long-established alternatives. As researchers emphasize “natural” should not automatically be considered synonymous with safe or effective, the most important consideration is whether an insect repellent has been thoroughly evaluated for both safety and performance1.
Common plant-based ingredients historically used as insect repellents include lemon eucalyptus, citronella, Neem, and different essential oils. In communities across Europe and North America, “natural” smelling repellents are often preferred because plants are perceived as a safe and trusted means of insect bite prevention. But scientists are emphasizing that there is a need for rigorous standardized studies on these plant-based ingredients in order to better evaluate natural repellent compounds. Long-established synthetic active ingredients have undergone stringent testing and have to provide strong safety profiles to be approved and sold to consumers. Many plant-based repellents however contain compounds that should be used with caution as they lack the testing that synthetic alternatives have undergone.1
While some natural repellents can provide meaningful insect protection, their effectiveness and duration can vary significantly depending on the ingredient and formulation.
How Effective Are Common Natural Repellents?
Lemon Eucalyptus (PDM)
Derived from lemon eucalyptus, PMD is the only plant-based active ingredient specifically recommended by the CDC for use in disease-endemic areas due to the low risk to human health. While it does demonstrate clinical effectiveness, the active ingredient tends to be highly volatile, rapidly evaporating after a short period of time and leaving the user unprotected. Like many plant-derived compounds, PMD duration of protection depends on formulation and application, with the repellent effect only lasting from several minutes to several hours.1
Citronella
Citronella today is one of the most popular natural repellents on the market. This active ingredient has found its way into many commercial insect repellents due to its familiarity with consumers, rather than its efficacy. Citronella is used at concentrations of 5-10%, lower than most other commercial repellent active ingredients, because higher concentrations may increase the risk of skin sensitivity. Protection generally lasts around 2 hours as the active compound evaporates rapidly. There are relatively few studies that have been carried out to determine the efficacy of citronella as an insect repellent.1
Neem
Neem is extracted from the seeds of the neem tree, and must be significantly diluted in repellents since it is a potent, heavy oil.2 The EPA has not approved Neem for use as a topical insect repellent. While it has a low toxicity, it can cause skin irritation when not diluted properly.1
Essential Oils
Essential oils commonly used as insect repellents are distilled from members of the mint family including culinary herbs, aromatic grasses, and pine and cedar families. These plants are often used for food flavoring or for perfume, which may explain the association with these oils as safer natural alternatives. As they are highly volatile and rapidly evaporate, many essential oils have been shown to repel disease-vector insects for approximately 1-3 hours, although effectiveness varies by oil, formulation, and concentration. Likewise, essential oils are exempt from repellent registration through the EPA, and have been known to be skin irritating, especially in the presence of sunlight.1
Summary of Natural Repellents
Natural repellents can be effective against biting insects; however, their duration of protection, safety profiles, and performance can vary considerably depending on the active ingredient and formulation. While some plant-based repellents may provide meaningful short-term protection, consumers should evaluate both safety and effectiveness when selecting an insect repellent.
A Different Approach: Nature-Inspired Science with IR3535® and IMPEDE
The active ingredient IR3535® bridges the gap between nature and science. Developed by Merck in the 1980s, IR3535® is structurally similar to the naturally occurring amino acid b-alanine (a component of Vitamin B5). IR3535® is therefore a synthetic compound inspired by nature, developed to mimic natural biological processes to inhibit an insect’s sense of smell and taste. “Natural” does not always have to mean plant-derived – it can refer to compounds that are nature-inspired and biologically aligned. IR3535® is a nature-inspired synthetic ingredient with a proven safety profile.
IMPEDE uses IR3535® as its active ingredient, offering an alternative to products that rely on more traditional synthetic repellent formulations. By avoiding DEET and similar compounds, IMPEDE provides a product specifically designed for safe, frequent, and consistent use. Using the patented technology of STAYTEC™, IMPEDE keeps the active ingredient on the skin surface longer, preventing rapid evaporation. The result is a protection time of up to 14 hours. The IMPEDE formula is lotion-based, hypoallergenic, and dye-free, making it suitable for children, pregnant women, and those with sensitive skin. IMPEDE combines nature-inspired science with modern innovation to provide protection that is effective, safe, and environmentally responsible.
For insect repellent consumers, the most important question may not be whether the product is natural or synthetic, but whether it has been shown to be both safe and effective. IMPEDE offers a repellent solution that is nature-inspired, long-lasting, and extensively safety tested to provide optimum insect protection performance.