Can We Make Perfumes More Useful?

When odorless insect repellents have higher or comparable safety profile to the common perfume ingredients, why not combine them?

From Hiking in Hong Kong to Functional Perfumes

Last weekend, I was preparing for a hiking trip to Hong Kong. Hong Kong is a very special city, in one day you can arrive to the airport, go for a hike with a beautiful view, go wake surfing, work in the frontier research lab, give a talk, meet investors at a phenomenal fusion restaurant like Dim Sum Library or Mott32, and take a 14-minute train to Shenzhen. Yes, it is so super compact and you could do all that in one day. It is one of the reasons why it the highest life expectancy on the planet - over 85.5 years. But there are minor challenges. One of the minor minor challenges are mosquitos. These mosquitos are tiny but very stingy - I am very allergic. So I sat down with an AI system and did what I have done for two decades in drug discovery, which is to compare candidate molecules on hard endpoints rather than on marketing. DEET versus picaridin. Mechanism, toxicity classification, complete protection time, skin feel, material compatibility, regulatory history. I wanted the data, not the vibe. By the end of it I had settled on twenty percent picaridin, and I had also accumulated a small, precise picture of a compound that is odorless, chemically stable, gentle on skin, and near-perfect at doing its one job for eight to fourteen hours at a stretch.

And then a stray thought landed, the way the interesting ones usually do, sideways and uninvited. I asked whether anyone had ever put picaridin into an actual perfume, so that a single product would smell good and protect you. The answer was no. Nobody makes it. Picaridin is sold purely as a registered repellent, and perfume is sold purely as decoration, and the two categories have apparently never been introduced. That struck me as strange. I spend my days at an AI drug discovery company designing novel molecules with genuine therapeutic intent, applying rigor to substances that go inside the human body. Meanwhile the fragrance industry, which puts its products directly on skin every single day, still treats scent as an ornament and asks nothing more of it. Why?

Fragrance Resists Innovation

This is the same error I wrote about when I looked at clothing. The fragrance industry is trapped in a nineteenth and twentieth century paradigm in which the entire point of a perfume is decoration and status signaling. You smell nice, you signal taste or money or seduction, and the product does no work beyond that. In the last decade the industry bolted on a second story, the “clean beauty” narrative, which claims to be about safety but is really about vibes. And here is the part that genuinely irritates me as someone who reads toxicology data for a living: the clean-fragrance movement frequently makes products that are less safe while sincerely believing the opposite.

The logic error is the “natural equals safe” heuristic, which is one of the most durable and least defensible ideas in all of consumer health. Citrus oils, lavender, and tea tree oil are among the most common causes of contact allergy and skin sensitization on the planet. Citrus oils in particular are phototoxic, meaning they can trigger a skin reaction when you go out into UV light after application, which is exactly what happens when you wear perfume and then step outside. A “natural” perfume loaded with essential oils is, from a dermatological standpoint, often a more hazardous product than a minimalist synthetic one. Meanwhile the real endocrine concerns in mainstream perfumery are chemicals most consumers never think about: phthalates, especially diethyl phthalate used as a solvent and fixative, and synthetic musks like galaxolide and tonalide. These interfere with estrogen, androgen, and progesterone signaling, they bioaccumulate in fat tissue, and they have been detected in human breast milk, body fat, and umbilical cord blood.

So the consumer fixates on a “chemical-sounding” name like picaridin and recoils, while happily applying a fixative that shows up in cord blood. This is the category error in miniature. People are optimizing for how a word sounds rather than for what a molecule does. My worldview, in fragrance as in everything, starts from primum non nocere and from the refusal to accept inherited defaults just because they are old. If we are going to put something on our skin every morning, I want to know two things: does it do something useful, and is it actually safe when you measure it instead of when you feel it. Decoration alone is a waste of surface area.

Picaridin as the Case Study

Let me introduce the compound properly, because it is a small masterpiece of deliberate design and it makes the point better than I can. Picaridin, also called icaridin, was developed by Bayer in the 1980s under the lab code KBR 3023 and commercialized as Bayrepel. What I find elegant about it is the design philosophy. Bayer used molecular modeling to target arthropod odorant receptors, and they built a molecule that mimics piperidine, a compound found in black pepper plants of the genus Piper. This is engineering, not foraging. They wanted DEET-level efficacy with a better safety profile, no strong odor, and no greasy feel, and they got it. It was first released in Europe and Australia in 1998, the US EPA registered it in 2001, US consumer products arrived in 2005, and after Bayer spun off Lanxess and Saltigo the trade name became Saltidin in 2008.

Compare that to DEET, which arrived the way so many mid-century chemicals did, more or less by brute-force screening. Samuel Gertler synthesized it at the USDA in 1944, one of more than seven thousand compounds screened originally for insecticidal use. Its repellent properties were recognized around 1952, the US Army adopted it after the war for jungle warfare, and it reached civilians in 1957. DEET works, and it has decades of data behind it, and its serious neurotoxic events are genuinely rare, roughly one seizure per hundred million users and almost always tied to ingestion or gross overapplication. But DEET is also a plasticizer. It degrades nylon, spandex, rayon, and watch crystals. It has a smell many people dislike. It feels unpleasant on skin.

The head-to-head data is what settled it for me. A 2018 review of eleven studies in the Journal of Travel Medicine found little difference between equivalent concentrations of picaridin and DEET, with some evidence that picaridin persists slightly longer. A twenty percent picaridin formulation gives roughly eight to fourteen hours of complete protection time, which is the time to first bite rather than a vague percentage of risk reduction, and it performs well against ticks, biting flies, gnats, chiggers, and sandflies. The EPA classifies it in Toxicity Category III to IV, meaning slightly to practically non-toxic across oral, dermal, and inhalation exposure, with no evidence of carcinogenicity, developmental, reproductive, or neurotoxicity in its review, and it is considered safe for pregnant women and children when used as directed.

Now here is why I could not stop thinking about it as a fragrance companion. Picaridin is odorless. It is pH-neutral. It is chemically stable and does not react with common fragrance families. It does not damage synthetic materials. It is, in other words, the rare functional active that asks almost nothing of the formulator and clashes with nothing. A brief but necessary disclaimer before I go further: none of this is medical advice, and anyone experimenting with an active like picaridin at home should follow the label directions exactly and consult a professional if there is any doubt, especially regarding children, pregnancy, or existing skin conditions.

Design Principles for a Functional Fragrance

If I were going to specify this product the way I specify a molecule’s target profile, I would write it down as a set of principles. Here are the ones I would refuse to compromise on.

1. Efficacy first, and efficacy must be registered, not implied. The active ingredient has to carry real regulatory efficacy data, the kind you can cite. Complete protection time in hours, measured in controlled studies, from a compound with an EPA registration. This is the whole difference between a functional product and a decorative one dressed up in functional language. Picaridin at twenty percent qualifies. A vague blend of “protective botanicals” does not, because botanical repellents are generally weaker and shorter-lasting per the literature. If the label makes a functional claim, the claim must survive being measured.

2. Chemical compatibility between active and scent is non-negotiable. This is where fragrance craft and formulation chemistry have to talk to each other. Picaridin is stable with alcohol-based, pH-neutral carriers and with woody, resinous scent families. Oud and musk pair with it beautifully, both because they are pH-neutral and stable and because picaridin’s own odorlessness means it will never fight the composition. The specific risk to flag is acidic essential oils, citrus above all, which could affect ester stability over shelf life. So you either avoid them or you test them rigorously with real stability studies across the product’s shelf life. You do not guess.

3. Regulatory honesty about what the thing legally is. This is the hard part, and it is where most people attempting this would cut a corner they should not. Picaridin is a registered pesticide in most jurisdictions. That means a picaridin fragrance is not merely a cosmetic; it is a registered repellent that also happens to smell like a fine perfume, and it must be labeled and sold as such. The Fix: you navigate the pesticide-registration pathway country by country rather than pretending you can slip an active into a cosmetic and call it a fragrance. What exists now: the pathway is actually cleaner than you might expect in many jurisdictions precisely because picaridin is already an approved topical repellent, so the active is not the obstacle. The obstacle is the honesty and the paperwork, and a founder who tries to route around either will deserve the enforcement action they eventually receive.

4. Stack the utility in layers. A repellent that also smells sophisticated is already two functions. But the same surface of skin can carry more. Broad-spectrum UV filters for the long hours outdoors that a repellent implies you are going to spend. Light moisturizers and humectants to counter the drying effect of wind and altitude. Soothing botanicals such as aloe or centella asiatica to calm skin and any bites that slip through after the protection window closes. Each layer is worn on the same skin at the same time, so the marginal cost of adding a function is low and the utility compounds.

5. The one-bottle travel thesis. This is the emotional and practical core of the idea. The Fix: a single elegant product that replaces the separate repellent tube, the sunscreen, the after-sun lotion, and the perfume you were going to pack anyway. What exists now: nothing that does all four with a real repellent active. Travelers and outdoor professionals already ruthlessly optimize pack weight and count, and the person who will pay a premium for one item that does the work of four is not a hypothetical, it is a large and well-understood customer. I felt exactly this friction packing for New Zealand, staring at three bottles that all had to go on my skin in sequence anyway.

6. Safety by formulation, which is the actual safety story. The clean-beauty movement told the wrong story. The real safety story is IFRA compliance, deliberate avoidance of phthalates as solvents and fixatives, avoidance of the bioaccumulating synthetic musks, and avoidance of phototoxic and high-allergen naturals like citrus, lavender, and tea tree. Counterintuitively, a minimalist formulation built on carefully chosen synthetic aroma chemicals in a pH-neutral alcohol base is frequently the safer product than a “natural” one, because you control every input and you can exclude the known offenders. “Natural good, synthetic bad” is not a safety framework. Measured toxicology is.

7. Honest market sizing. I will not oversell this. The global insect repellent market is roughly six to twelve billion dollars, the functional fragrance market is around twelve billion in 2026 and projected toward roughly twenty billion by 2035 at about six percent annually, and the broader fine fragrance market runs fifty to sixty billion. A picaridin-plus-fragrance product sits in a small but real overlap of those, most plausibly launching in premium travel and outdoor retail before any expansion. It is a niche. But it is a niche with an unusually motivated buyer and, at present, no serious competitor doing it correctly.

The Competitive Landscape, and Why It Is Aiming at the Wrong Target

This idea is not entirely unattempted. There are real products in the market that combine fragrance with insect protection. The BUZZ Skin sells a fine-fragrance bug-repellent eau de parfum line. Heretic Parfum’s “The Entomologist” is an EPA-compliant natural bug spray built and marketed as a luxury fragrance with cedar, thyme, rosemary, and geranium notes. Aromaflage uses vanilla-derived functional notes marketed to disrupt the cues mosquitoes use to find you. These are genuine, thoughtful products made by people who saw the same gap I saw, and I respect that they shipped something.

But every one of them is optimizing for the wrong axis. They all rely on natural botanical actives, essential oils and plant compounds, because their brand thesis is naturalness and “clean” positioning. And per the efficacy literature, botanical repellents are generally weaker and wear off faster than picaridin or DEET. So these products are making a real functional claim on a foundation that cannot fully deliver the function. They chose the marketing story that consumers currently reward, naturalness, over the axis that actually matters for a repellent, which is complete protection time backed by registration data. That is a values decision, and I understand why they made it, but it means the actual open opportunity is still open.

The unfilled position is the one that pairs EPA-grade efficacy with genuine fragrance craftsmanship. A twenty percent picaridin active, giving eight to fourteen hours of real protection, inside a serious oud-and-musk composition made by someone who actually knows how to build an accord, in a safe IFRA-compliant base with UV and skin-soothing layers stacked on top. That product does not exist. The existing players ceded the efficacy ground to keep the naturalness story clean. I would rather keep the efficacy and tell an honest safety story instead, because the honest safety story, once you actually read the toxicology, favors the well-designed synthetic anyway.

Why This Is the Same Idea, Smaller

I keep coming back to the same underlying conviction across everything I write in this series. The everyday objects we live inside, the clothing on our bodies and now the scent on our skin, should stop being passive decoration and start being functional infrastructure for a longer and healthier life. I organize my thinking about that life around peakspan over healthspan over lifespan: not merely surviving longer, not merely staying free of disease longer, but staying at the top of your capacity as long as possible. Most of that project happens at the level of biology and medicine, which is where I spend my actual working hours. But some of it happens at the level of the mundane objects we accept without questioning, and those objects almost always turn out to have been designed for a world that no longer exists, or designed for nothing at all beyond appearance.

A functional fragrance is a low-stakes version of the same discipline that drives the drug discovery work I do. You take a category, you refuse to accept its inherited default, you ask what job it could actually do, you identify a molecule with real registered efficacy, you check its safety with data instead of intuition, you confirm its chemical compatibility, and you build the thing deliberately. The scale is tiny and the consequences of getting it wrong are a mediocre perfume rather than a failed therapeutic, but the method is identical. Rigor does not care whether the target is a cancer pathway or a bottle of scent. It only cares whether you measured.

I should be honest about what this is and what it is not. This is a molecule-level idea, not a business plan. I have not modeled the unit economics, I have not talked to a fragrance house or a regulatory consultant, and I have not decided that the world urgently needs another product from me. Whether anyone actually builds a picaridin perfume, and whether the pesticide registration and consumer skepticism and formulation stability all resolve in its favor, is a separate question from the one I set out to answer. The question I set out to answer was simply whether we can make perfume more useful, and the answer, once you replace nostalgia and marketing with chemistry and toxicology, is clearly yes. Someone should. It might not be me. But the fact that it does not yet exist, in a market that already sells worse versions of the same instinct, tells me the gap is real and the defaults are, as usual, waiting to be questioned. I will see how easy it is to find picaridin that I can combine with my regular fragrance. Next time you meet me at a conference, chances are high I will have the 20% picaridin solution on me with some perfume.