The Opportunity
We are seeking a Cosmetic Scientist to lead the formulation of a natural hydrogel cosmetic with outstanding spreadability, quick dry-down, and long-term stability. This is a three-month, full-time Contract role focused on developing a minimalist, INCI-compliant gel using only natural ingredients. Throughout the project, you'll report directly to our Chief Scientific Officer and collaborate closely with the R&D team.
You'll begin this contract remotely for the first month, focusing on formulation planning and ingredient sourcing. Over the following two months, you'll work on-site at our San Francisco lab carrying out hands-on formulation, testing, and iterative optimization.
We recognize that this may require temporary relocation, and we provide full travel compensation to support candidates during the in-person phase. Top candidates will bring deep expertise in hydrogel chemistry and a strong track record of developing high-performance cosmetics with minimal, natural ingredient lists.
Required Qualifications
️ Master's in Chemistry, Cosmetic Science, Pharmaceutical Sciences, Polymer Science, or a related field
️ 4+ years of hands-on experience developing clean-label or natural cosmetic products
️ Demonstrated expertise with natural hydrogel systems and associated formulation challenges
️ Familiarity with sourcing botanical and natural ingredients from raw material suppliers; skilled in evaluating technical specification sheets, verifying INCI compliance and quality certifications, assessing lead times and MOQs, and managing sample procurement for traceable inputs.
️ Experience rapidly reverse-engineering existing cosmetic products
️ Familiarity with pH adjustment and freeze/thaw + heat/cool stability testing
️ Experience with cosmetic preservative systems, specifically the antimicrobial properties of natural polysaccharides.
️ Ability and willingness to work on-site at our San Francisco, California headquarters (this is an in-person contractor role)
️ U.S. Citizenship, legal permanent residency, or proof of existing work authorization
Experience in the following is highly desirable
Ph.D. in Chemistry, Cosmetic Science, Pharmaceutical Sciences, Polymer Science, or a related field
Prior formulation work using natural hydrogel-forming agents, including microbially-derived polysaccharides (e.g., xanthan gum, gellan gum, sclerotium gum, pullulan, biosaccharide gums), marine-derived polysaccharides (e.g., carrageenan, alginate, agar), and plant seed-derived or botanical gums (e.g., konjac mannan, guar gum, locust bean gum, tamarind seed polysaccharide, tara gum), or other natural gelling systems with documented cosmetic use
Strong understanding of gel-sol transitions and hydration kinetics in natural polymer systems, including how polymer concentration, temperature, shear, and pH affect gel formation and breakdown; familiarity with ionic crosslinking (e.g., calcium- or magnesium-mediated) in systems like alginate or carrageenan, and how mono- and divalent salts modulate viscosity, clarity, and syneresis in low-buffer, minimal-ingredient formulations
Designing and tuning hydrogel rheology from first principles-understanding viscoelastic behavior, including thixotropy, shear-thinning, yield stress, and recovery kinetics-to optimize spreadability, absorption, and structural stability; with hands-on expertise using rheometers (rotational and oscillatory), viscometers (cone-plate, capillary, Brookfield), texture analyzers (compression and probe-based), high-shear mixers, homogenizers, pH meters, centrifuges, analytical balances, and environmental chambers to evaluate performance across stress, strain, temperature, time, and packaging conditions.
Experience with compatibility testing across common cosmetic packaging materials, with an understanding of potential interactions such as plasticizer leaching, sorption of active ingredients, oxidative degradation, paneling, and stress cracking under heat
Transparent Contract
️ 1-month full-time (remote) + 2-months full-time (in-person in San Francisco)
️ $37,500 total contract value
️ Full travel reimbursement
️ Independent contractor (1099-NEC)
Application Process
Interested contractors should submit their resume and a one-page cover letter clearly outlining their most relevant experience. Taxa is an equal-opportunity company committed to fostering an inclusive workplace. Offers are contingent upon successful completion of reference and background checks.