What is ISTI?

ISTI is the acronym for the Integrative Sex Therapy Institute. Founded in 2014 as Sex Therapy U, Dr. Tammy Nelson and our Advisory board design a training curriculum for therapists to meet the challenging and changing social trends in society. Expert professionals share knowledge of their specialties relating to sex therapy and/or couples therapy. Tracks include Certified Sex Therapist (CST), Certified Sexuality Counselor (CSC), Certified Sexuality Educator (CSE), Certified Sex and Couples Therapist (CSCT), and recertification.

Is ISTI certified?

ISTI is a certified Organizational Provider for the American Association of Sexuality Educators, Counselors and Therapists (#10-102B) and all courses are taught by a Ph.D., LCSW, MSW, or LPC. All courses are clinical in nature and instructors are experts in their field. ISTI maintains strict files for each course taught that include a syllabus, reference material, handouts and the presenter’s CV. This information is available for you if you wish to submit it to your certifying board.

Integrative Sex Therapy Institute is approved by the American Psychological Association to sponsor continuing education for psychologists. Integrative Sex Therapy Institute maintains responsibility for this program and its content.

 Who accepts ISTI CE’s?

We strongly recommend you contact your local certifying organization on courses they accept for CEs as these can vary by organization, state, and event.

(AASECT) American Association of Sexuality Educators, Counselors and Therapists .  Completion of our courses does not ensure or guarantee AASECT certification. For further information contact info@assect.org, call 202-449-1099, or go to the AASECT  website.

How do I start?

You can start taking classes at ISTI without enrolling as a student. Some students take the Integrative Sex and Couples Certification Training through PESI. The course hours from PESI will transfer to ISTI and can serve as a stepping stone to certification. You can find information for enrolling with ISTI located here, or you can Apply to our program here on the website.

What does it cost?

Detailed information about the cost of attending ISTI for your CST or your CSCT is located here on our website. Purchased individually each course averages between $35-50/ hr. Registering for the whole program gives you discounts and a payment plan. Application to ISTI is $50.


Hours Required

Does this include SAR

Ad Hoc


Program Price
















**Supervision hours are arranged directly with the supervisor and costs are not included in the pricing above.

Are there discounts, financial assistance, or a payment plan?

Scholarships/Internships: Dr. Tammy offers scholarships and internships throughout the year. Be sure to inform us at Admin@integrativesextherapyinstitute.com if you are interested in signing up for her mailing list or to be added to the scholarship interested list. We offer all students payment plans.

Early Registration is offered for nearly every live course taught. eLearn bundles often have discounts available throughout the year.

Can I take classes before I am licensed?

You can take classes before you are fully licensed and before you have a graduate degree.  Register for the whole program or take classes one day at a time as you are interested in the topics.

When you have taken all of your courses and are ready to apply for certification you will need to be licensed and have malpractice insurance. You must also finish your clinical hours in order to receive your certification.

In order to start supervision, if you want your hours to count toward your potential certification, you need to be licensed or working under a licensed supervisor at your place of employment.

Certified Sexuality Counselors and Certified Sex Educators have different requirements.