Most spas choose their products from a distributor catalogue. Resonance Marin took a different path. Every cleanser, serum, oil, mask, and balm used in our treatments is formulated and produced in our own lab, in the same building as the treatment rooms. This article is the long answer to why, and the honest story of how a Marin spa ended up running a formulation lab when neither of those things was the original plan.
It started with frustration.
Resonance opened in 2017 as a clean-beauty-focused Marin spa. The intention was modest: be more selective about products than most spas were, partner with the best clean lines available, deliver a results-driven experience using product choices we could defend ingredient by ingredient.
By the end of the first year, the limits of that approach were obvious. Even the best clean-beauty brands left gaps that didn't make sense for the work we were doing. A serum that worked beautifully on most clients but contained one ingredient that triggered pregnant clients. A cleanser that we loved for sensitive skin but came in plastic packaging that contradicted our values. A clinical mask that performed but required a synthetic fragrance to mask the active scent. Each product was a compromise on something.
The deeper issue: we couldn't customize. When a client came in with reactive, hormonal, post-surgical, or recovering skin and we needed a slightly different formulation, slightly more lactic acid, a different humectant ratio, no fragrance, there was no way to make that adjustment. The product was the product. We were locked into what someone else had decided was best, often years before, often without the kind of treatment-room feedback that should inform that decision.
2018: the first experiments.
The first formulations began in 2018, back-of-house experiments in a corner of the spa, refined on willing clients in the treatment rooms. The first product was an aromatherapy oil blend for body work, customized for clients with fragrance sensitivities. The second was a clarifying mask formulated specifically for clients who were too reactive for the commercial options we had been buying.
The methodology was self-taught at first, YouTube videos, textbooks, conversations with chemists, attempts at sourcing professional-grade actives. The work was driven by Daniella Inbar, whose background is in design and product development, not formal cosmetic chemistry. When the limits of self-teaching became obvious, she enrolled in formal cosmetic chemistry coursework. She never finished the degree, the lab and production work took over before she could. The expertise is real, the credentials are partial, and the methodology that emerged from that combination is closer to clinical practice than academic chemistry.
A note on credentials
We are explicit about this because the alternative, overclaiming credentials, is more common in this industry than it should be. Where formulations require expertise beyond the lab's in-house capabilities, INBAR+co works with chemists, dermatologists, and clinical researchers as collaborators. This is how the work has always been done: practice first, formal study second, expertise borrowed when needed.
2019: a lab, a name, a line.
By 2019, the back-of-house experiments had become a formal operation. The lab was built into the building, staffed and equipped. The first INBAR+co products went on the shelf, a small line of clarifying mask, body oil, and a hydrating essence that grew out of the most-used formulations from the treatment rooms.
The retail line was not the original plan either. We started making products because we needed them in the treatment room. Clients started asking if they could take them home. The boutique grew because demand grew. The website that became inbar-co.care came later, and now ships globally from our Corte Madera location.
The thing that has not changed since 2019 is the testing methodology. Every product begins on a treatment table. An esthetician or therapist identifies a gap. The lab responds with a prototype. The prototype gets used in real treatments. It is refined or rejected based on what happens. If it works repeatedly across diverse skin types over months of use, it becomes a product. If it doesn't, the formula goes back. We call this the Living Formulation System, described more fully on our Formulations page.
What we couldn't get from a distributor.
Several specific things became impossible to compromise on, and these are what drove the lab's growth:
Transparency
Many spa product lines hide behind "proprietary blends", ingredient lists that disclose only the broad category, not the specific actives or their concentrations. When an esthetician applies that product to a client and the client asks what's in it, the honest answer is often "I don't know exactly." For a spa that was making specific claims about treatment outcomes, that wasn't sustainable.
INBAR+co publishes the full ingredient list for every product. Estheticians and practitioners know exactly what's in the formulation they're applying. Clients can review the deck before booking. The lab's formulation logic is documented and defensible.
Pregnancy safety
Standard spa massage and facial products often contain essential oils that are contraindicated during pregnancy, clary sage, rosemary, juniper, jasmine, basil, and several others have uterine effects that make them inappropriate for prenatal sessions. Most commercial lines don't disclose enough about their fragrance blends to verify safety.
Every INBAR+co product used in our prenatal protocols is formulated with full pregnancy safety in mind, disclosed essential oils only, no contraindicated ingredients, fragrance-free options available. Our prenatal massage safety article walks through why this matters.
EU regulatory compliance
The European Union bans over 1,300 ingredients in cosmetics. The US FDA bans 11. The gap is not a technical disagreement about safety, it's a regulatory difference, and most commercial spa products in the US are formulated to the lower standard because that's what they're required to.
From the very first batch of Thermal Relief Cream we made in our spa, INBAR+co has complied with EU regulations. Not as a marketing position, as a basic safety floor. The same product is sold in California or Berlin. Same ingredient deck, same compliance.
Plastic-free packaging
Almost every commercial spa product comes in plastic. Even brands that market sustainability ship in plastic tubes, plastic bottles, plastic caps. Reducing plastic by 30-40% is sometimes called "sustainability." Eliminating plastic entirely was not a choice we could make through purchasing, we had to make it through formulation.
INBAR+co packages in aluminum tubes, glass bottles, FSC-certified paper boxes. Custom-designed aluminum spray nozzles took eighteen months to source. There is no plastic anywhere on the product. More on our planet-positive practices →
The customization loop
This is the thing distributors structurally cannot offer. When we identify a new pattern in the treatment rooms, a recurring need that no current product addresses well, we can adjust an existing formula or develop a new one. The product is in our hands. The feedback loop is direct. The change happens in months, not a multi-year corporate product cycle.
"Owning the formulation means owning the feedback loop. When the science changes, or when our understanding of a client's skin deepens, the product can change. That is the structural advantage of having the lab inside the building."
The timeline.
What this means for clients.
The practical result of the lab-in-the-building model, in the treatment room:
Your protocol can be customized in ways no other spa can offer. Sensitivity to fragrance? Switch to the fragrance-free version of the body oil. Reactive skin? Adjust the active concentration. Pregnant? Move to the full prenatal-safe formulation. The esthetician makes these calls in real time, on the day, based on what they're seeing on your skin.
Your esthetician knows what's in every product. Not the broad category. The specific actives. The exact concentration. The buffering agents. If a client asks "what is the lactic acid percentage in this peel," the answer is specific.
You can continue the exact treatment at home. The retail INBAR+co products are not "consumer versions" of the professional product. They are the same formulations, in retail packaging, with the same actives and the same concentrations. The Hydratech Cleanser used in your facial is the same Hydratech Cleanser available at inbar-co.care.
Your treatment is more environmentally responsible than the industry standard. Plastic-free packaging across the entire line. EU-grade ingredient compliance. Lab waste minimized through small-batch production. Energy sourced from Marin Clean Energy Deep Green tier. The product on your skin and the operation that made it are aligned with the values most clients now expect from a Marin spa.
What we still don't make.
An honest list of what is not produced in our lab and where it comes from:
- Some specialized clinical actives, exosomes, peptide complexes, certain biotech-derived molecules, are sourced from specialist suppliers that maintain the cold chain and active stability required. The active is sourced; the formulation around it is ours.
- Equipment-specific consumables for RF Microneedling, HIFU, and similar device-based treatments are supplied by the equipment manufacturers, as they are part of regulated medical device protocols.
- Some sustainable retail partners, the boutique stocks brands aligned with our values (Mariage Frères, Guanabana, Native Union, IZIPIZI, Ilex Studio), these are curated, not formulated.
Everything else, every cleanser, every serum, every mask, every body oil, every balm, every amenity, is made in the lab in Corte Madera.
The bottom line.
This is not a marketing position. The lab is a substantial operational commitment, more expensive than buying from distributors, more complex than running a typical spa, harder to scale than a franchise model. We built it because we couldn't get what we needed any other way, and we've kept it because the work that comes out is better than the work we could have bought.
If you book a treatment at Resonance Marin, the product on your skin was developed and tested in the building you're in. You can ask what's in it. You can take it home. You can return next month and ask for an adjustment. The lab is not a story. It is the structural reason the work is what it is.