Professional and Master Certification in Aromatherapy and Essential Oil Science


Professional and Master Certification in Aromatherapy and Essential Oil Science

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Become a certified clinical aromatherapist
and master the art of aromatherapy.

For the serious student who is seeking the most comprehensive aromatherapy certification training available, we offer our Professional and Master Level Certification Programs combined, granting you a Diploma in Advanced Aromatherapy.

This is your opportunity to cultivate a successful career and have a significant impact on the field. 

Becoming an Essence of Thyme Certified Clinical Aromatherapist also provides you with the knowledge to venture into teaching and research careers.


After completing the Gold Standard, our graduates have successfully...

  • launched their own product line
  • opened their own retail stores
  • developed their own course
  • presented at conferences
  • conducted research
  • published articles

Regardless of the path you choose, Essence of Thyme will always have your back... even after you graduate.

Do you ever think about the opportunities that being a certified clinical aromatherapist could offer?

You’re seeking a comprehensive education so that you can provide the utmost service and knowledge to your clients, customers, or students.

Earning your Diploma in Aromatherapy from a credible and professionally recognized school will open new doors for you, empowering you to become a leader in the field.

You can expand your business, teach aromatherapy, contribute to the field through research, publications, and speaking engagements, and share your work on a level in line with industry experts.

Are you looking for an in-depth aromatherapy certification program that will help you realize your vision? 

You've found the Gold Standard. 

Make your goals happen with our signature aromatherapy diploma program. Our comprehensive, evidence-based certification programs exceed the criteria set forth by professional aromatherapy associations, and we are the only aromatherapy educational institute recognized by 5 international aromatherapy associations.

Our instructors and faculty are international experts with decades of combined experience as practitioners and in business development, retail service, marketing, conducting scientific research, and publishing articles in peer-reviewed journals, as well as speaking worldwide at aromatherapy conferences.

You'll be fully supported.

Not only do we offer one-on-one support so you have direct access to our renowned instructors, but you also have an attendance pass to join our interactive monthly live lectures — so you stay motivated and on the cutting edge, learning from experts in the field on topics ranging from essential oil chemistry, plant sustainability, marketing your aromatherapy business, developing courses, and effectively communicating as an educator and practitioner.

And we didn’t stop there!

You also get...

  • your own personal mentors as you complete your case studies and research project 
  • access to our private student forum, led by our expert instructors
  • monthly live, interactive open forums where you connect with instructors and meet your fellow students
  • access to our Essential Library: a comprehensive 10-year archive of recordings and supplemental material presented by leading experts from all over the world, as well as resources above and beyond your curriculum

This is one of the most comprehensive and internationally recognized aromatherapy certifications available today. We’d love for you to be a part of it!

Essence of Thyme College of Holistic Studies sets the Gold Standard for aromatherapy certification.

Professional aromatherapist

Advanced skills to grow your career

Essence of Thyme provides you with the knowledge to venture into entrepreneurial, educational, and research careers. You'll be prepared to build meaningful connections and advance your career in a rapidly growing field through effective public speaking and presentation skills, teacher training, research analysis, and business expansion.

Extensive instructor expertise

Essence of Thyme's instructors bring a unique combination of skills to the table. You will receive the tools you need to write articles for peer-reviewed journals, and easy ways to constructively read research articles. This builds your credibility and audience fast!

Our team also works with students on research design for the field and the lab, statistical analysis, and exploring other ways to actively get involved in research that will help advance the field, all while protecting threatened medicinal and aromatic plants.

This is exclusive to our school and an invaluable asset to our students.

Dr. Kelly Ablard in lavender field
Screenshot of online aromatherapy course at Essence of Thyme College of Holistic Studies

User-friendly online curriculum

You'll study a progressive curriculum that is organized, user-friendly, and created with the utmost attention to detail.

Your course is available to you 24/7, 365 days a year, on our state-of-the-art online learning platform for an easy learning experience. 

No matter where you are and in what part of the world you live, learning how to become a certified aromatherapist is convenient and always accessible.

Because the program is self-paced, you can take as long as you like to complete it, with no time limit.

Here’s what you get when you learn from us.

Our dedicated and inspirational team promises to support your success and to provide you with the skills you need to create a unique path as a highly knowledgeable, sustainably minded, and dynamic aromatherapy professional.

Guidance and Motivation

We take guiding and motivating you on your journey very seriously. You get direct mentorship and support from our expert team, exclusive access to live talks by leading experts in the field, personal advising and monthly open forums, and a private student forum to connect with students from all over the world. This goes far beyond what you get with any other online aromatherapy certification program.

Updated and Unique Curriculum

Essence of Thyme sets the gold standard in aromatherapy education. We ensure a comprehensive, self-paced, and interactive online curriculum that is updated annually. Our curriculum is unique because it includes videos and lessons by top experts in the field which have been specially developed just for our programs. 

Conservation Consciousness

We're committed to the protection of threatened essential oil-bearing plants and to ethical sourcing of essential oils. Essence of Thyme is a member of the Airmid Institute Plant Protector Program, providing you with the right tools to protect and heal the very same plants that we use for healing.


We love to provide you with extra perks to help you stay motivated while learning! Quizzes and prize drawings, special discounted rates on additional Essence of Thyme expert-led courses, and a one year subscription (compliments of Essence of Thyme) for Blend Precisely or Dropsmart are just a few of the ways you'll benefit from being an Essence of Thyme student.

Qualify for Professional Associations at the Highest Levels

Upon successful completion of the Gold Standard Advanced Diploma in Aromatherapy, you are eligible to join these international professional aromatherapy associations at their highest levels of membership: 

  • Alliance of International Aromatherapists (AIA): Advanced Practice Clinical Aromatherapist (APCA)
  • National Association for Holistic Aromatherapy (NAHA): Certified Clinical Aromatherapist (level 3)
  • Canadian Alliance of Aromatherapy (CAOA): Registered Aromatherapist® - RA® and Essential Oil Therapist® - EOT® (level 3)
  • International Federation of Professional Aromatherapists (IFPA): Full Member
  • New Zealand Register of Holistic Aromatherapists (NZROHA): Professional Member

You’ll be recognized as a certified aromatherapist with international credibility, qualify for practitioner insurance, and remain connected to leading experts and breakthroughs in the field through conferences, webinars, and newsletters.


The Essence of Thyme Gold Standard Program: Advanced Diploma in Aromatherapy

You'll study:

  • 93 essential oils 
  • 33 carrier oils and other mediums
  • 12 hydrosols
  • 27 CO2 extracts
  • 28 modules with accompanying video highlights and printable reading materials

You'll get:

  • comprehensive, detailed monographs for 93 essential oils and 33 carriers including therapeutic benefits, safety, conservation status, and history
  • expert personal mentorship and support as you complete your 30 case studies and a research paper
  • lifetime access to your course materials

As an Essence of Thyme Advanced Diploma student, you also get:

  • access to the Essential Library: a comprehensive archive including 10 years of monthly lectures, practitioner manuals, and additional study resources  
  • personal support via email or our private student forum
  • 1-year membership in the LabAroma Grow plan (included with part 1 of your Diploma, the Professional Level Certification Program)
  • a 20% discount on Airmid Institute membership and access to all benefits of the Airmid Institute Plant Protector Program
  • 1-on-1 private advising with Colleen Thompson, founder, or Kelly Ablard, co-principal 
  • monthly live, interactive lectures with leaders in the field of aromatherapy and plant medicine 
  • no matter where you are in the world, you qualify for membership in 5 international professional aromatherapy organizations

Tuition and Payments

Our tuition is in Canadian dollars, which may be a significant savings in your country. Use the currency converter below to calculate your cost.

Pay in Full

$3800 CAD

one-time payment

  • Professional + Master Level Certification Programs combined, granting you a Diploma in Advanced Aromatherapy
  • 630-hour Level 3 AIA, NAHA, CAOA; IFPA Full Member; NZROHA Professional Member
  • includes one 50-hour elective 
  • qualify for membership in 5 international professional aromatherapy organizations

Payment Plan

$490.50/mo CAD

for 8 months

  • Professional + Master Level Certification Programs combined, granting you a Diploma in Advanced Aromatherapy
  • 630-hour Level 3 AIA, NAHA, CAOA; IFPA Full Member; NZROHA Professional Member
  • includes one 50-hour elective 
  • qualify for membership in 5 international professional aromatherapy organizations
  • $3924 CAD in 8 monthly payments of $490.50 CAD

Added Bonus

Joining a professional aromatherapy association is an important step in your career — it gives you credibility, qualifies you for practitioner insurance, and keeps you connected to experts all over the world. And nothing makes us happier than to see our students succeed. 

Essence of Thyme will pay $30 CAD toward your first-year student membership to the professional aromatherapy association of your choice! This offer is valid ffor 2 months after you pass your first midterm exam with a minimum of 80%. The association must be one that recognizes us (IFPA, AIA, NAHA, NZROHA, or CAOA).

This unique benefit is not offered anywhere else!

Your Path to Success

The Gold Standard Advanced Diploma Program consists of 2 freestanding certification programs. In total, it includes 50 contact hours, 28 modules, and your choice of one 50-hour elective. Your course content is divided into organized, manageable lessons that build upon each other.

Each lesson is presented to you one at a time, and how long it takes to complete each lesson is entirely up to you!

Each lesson is taught by Colleen, Kelly, or one of our expert Supporting Instructors. Lessons include a combination of videos, quizzes, worksheets, essential oil or carrier monographs, and reference charts that are all designed to help you build your reference library as a professional aromatherapist.

Our comprehensive monographs cover the history, chemistry, botanical description, conservation status, scent note, and therapeutic benefits of each essential oil.

One of the best ways to increase your success as a student and improve retention of your course material is to complete short assessments along the way. After each lesson, you will complete a multiple choice assessment to help support your learning. Once you have successfully passed each assessment, the next lesson will open up for you. And, of course, we're always available to answer your questions as you go along.

Get Started Today
Amber Horricks

Amber Horricks

The wealth of knowledge I am gaining is incredible! This is not like most online programs I have taken, as the instructors are always there to answer, guide, and support. Colleen and Kelly are an amazing team that wants to see students succeed.” 

The Gold Standard Advanced Diploma Includes Two Comprehensive Aromatherapy Programs

Part 1: Professional Level Certification Program

First, you will complete the Professional Level Certification Program, earning your 300-hour Level 2 certification as the prerequisite for your next step in the Gold Standard.

Part 2: Certified Master Aromatherapist Program

This 330-hour program delves even further into many of the topics introduced in the Professional Level Certification Program, and is the second portion of your Advanced Diploma studies.

You'll delve even further into:

  • conservation and sustainability
  • pharmacokinetics and  pharmacodynamics
  • application methods
  • aromatherapy and integrative health
  • chemistry
  • research

You’ll study:

  • 45 essential oils
  • 16 carrier oils
  • 18 CO2 extracts
  • 7 hydrosols
  • ...and one elective course of your choosing

You'll understand:

  • body systems: immune, lymphatic, integumentary, nervous, musculoskeletal, circulatory, respiratory, digestive, urogenital, endocrine, and olfactory
  • olfaction and human psychology
  • working with dementia
  • working in a care home environment
  • working in a hospice setting/end of life
Start Your Diploma Now
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Choose your advanced elective and grow your expertise 

The best way to be successful as an aromatherapist is to specialize in a particular area. This gives you the advantage of creating your own niche and becoming an expert in the field.

The Gold Standard Diploma Program includes one advanced 50-hour elective, included in your tuition. Options include the Essence of Thyme Teacher Training Program or aromatherapy for hospice. Once you’ve completed the Professional and Master Level coursework, you'll begin your elective. 

Cheryl Whitten

Cheryl Whitten, BA

“I’ve worked in aromatherapy since the early 2000s. After many years, I finally chose to certify my knowledge with Essence of Thyme. I found the program to be detailed and advanced beyond any other certifying aromatherapy program I’ve taken and with more clinical hours. With my background as a professional writer, I was able to publish my research paper in a peer-reviewed journal and formally present my case study research on aromatherapy and stress reduction at a Canadian Mental Health Association annual conference with the encouragement of Dr. Ablard. I continue to teach my own students around the world and very much enjoy the graduate access to continuing education and lectures from the College.”

Lead Instructors

You'll have hands-on support from our founders, Colleen and Kelly, who have decades of combined experience in education, research, sustainability, and the business of aromatherapy.

Colleen Thompson, RA

Colleen Thompson, Cert Ed, MIFPA, RA®, EOT®, CA


After 20 years in the field of banking, Colleen was completely transformed by the pain-relieving effect essential oils had on her chronic migraines.

Since that “aromatic” moment in 1995, she began her journey in the field of Aromatherapy and has been a Registered Aromatherapist since 1997.

She incorporated her business, Essence of Thyme Ltd., in 1995, and over the course of 12 years owned three aromatherapy stores and a holistic spa. In 2012, she completed the development of her Aromatherapy Certification Program which is offered through Essence of Thyme College of Holistic Studies.

Colleen’s practical experience of owning and operating aromatherapy stores, creating blends for the stores, as well as providing aromatherapy courses and workshops and various aromatherapy massages and complementary treatments is reflected in the program.

Kelly Ablard, PhD, RA®, EOT®, MIFPA


Kelly stumbled upon essential oils early in life and was amazed by their beautiful fragrances and healing benefits. But it wasn’t until years later, when she was working on her doctorate degree in biology, that Kelly was inspired to become a registered aromatherapist. It was then that she witnessed the astonishing connection between essential oil compounds and their use in communication by many species on the planet.

As a Conservation Aromatherapist™, this knowledge continues to help her protect threatened animal and essential oil-bearing plant species, which in addition to aromatherapy, is one of Kelly’s key areas of expertise.

Kelly is a certified and registered aromatherapist and holds a PhD in Biology and an MSc in Conservation. She currently conducts research in Peru on the Endangered rosewood (Aniba rosaeodora) tree. Please click here for her CV.

Expert Faculty

Essence of Thyme's faculty includes internationally acclaimed aromatherapy experts in diverse areas of specialization to help you focus your career goals. We bring these experts — and the experience of learning from them — directly to you, in exclusive lessons that are included in the Gold Standard Advanced Diploma in Aromatherapy.

Ann Harman hydrosol expert

Ann Harman

advanced hydrosols and their chemistry

Madeleine Kerkhof CO2 extract expert

Madeleine Kerkhof

advanced therapeutics and usage of CO2 extracts

Marika Fleri aromatherapy expert

Marika Fleri

aromatherapy and cancer

Join the hundreds of international Essence of Thyme graduates who are committed to bringing the Gold Standard of professional aromatherapy into the world.

As a graduate of Essence of Thyme College of Holistic Studies, you'll embark on your career knowing that you have received the Gold Standard for aromatherapy education.

Our strong community and formal recognition by 5 international professional aromatherapy associations will give you a sense of belonging and new friends. You'll be part of a dynamic movement that will support  and foster your professional growth, and you'll have many opportunities to make a difference in the field...and in the world!

Deena Peters 
EOT Graduate

Kirstin Tomas
EOT Graduate

Angie Kennedy 
EOT Graduate

Grace-Anne Post
EOT Graduate

Mary Monteiro EOT Graduate

Mary Monteiro
EOT Graduate

Johanne Trudel-Dekam EOT Graduate

Johanne Trudel-Dekam
EOT Graduate

Theresa Edwards EOT Graduate

Theresa Edwards
EOT Graduate

EOT Graduate Melissa Allen

Melissa Allen
EOT Graduate

Your benefits don't stop when you graduate!

Even after you graduate, you'll still receive support and benefits:

  • lifetime access to your course reading materials
  • exclusive discounted tuition on additional expert-led courses at Essence of Thyme
  • work collaboratively on research projects and publications
  • continued access to our private Student Forum and Essential Library
  • the option to partner with us as an Essence of Thyme affiliate, promote our aromatherapy certification programs, and earn income
Sign Me Up!

Frequently Asked Questions

Karina Langevin EOT Student

Karina Langevin

“Bonuses of being a student are: there is someone available to help out with ANY questions, tutoring options and the monthly lectures are a bonus to gain extra knowledge in the Aromatherapy field.”

Marina Khoury EOT Student

Marina Khoury

“After several searches and contacts with other schools, which did not convince me at all (lack of rigor and credibility), EOT was the one that won me over with its personalized, honest and very professional approach led by Colleen and Kelly. ”

Margaret MacLellan EOT Student

Margaret MacLellan

“I am very pleased with my decision to attend Essence of Thyme College of Holistic Studies and look forward to being able to continue to learn and help others through the safe and effective use of essential oils and aromatherapy."

Still have questions? 

If you have any questions before you sign up, we're here to help!

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