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D4 Psychology Clinic · Blackrock, Dublin

D4 Psychology Clinic Specialising in Psychotherapy and Hypnotherapy

At The D4 Clinic in Blackrock, Jason O’Callaghan combines clinical hypnotherapy and psychological techniques to help you understand your habits, make positive changes and work towards a healthier, more confident life.

Whether you’re struggling with weight loss, smoking, anxiety or stress, Jason offers a personalised approach designed around you.

Ireland's Highest Google Ranked Clinic

over 180+

Reviews

As seen on

Choose the Package That Suits You

Generic or Personal Download Session

A single comprehensive downloadable content

€99

Bronze

Single session + recording for home use

€199

Silver

3 clinic sessions

€595

Gold VIP

6 clinic sessions

€799

Platinum Executive

8 sessions, out-of-appointment support, priority support

€1997

All programmes are paid for in advance. Payments are non-refundable once made, subject to applicable consumer rights.

Blackrock, Dublin · By appointment

Success stories from D4 Clinic clients.

      EXCELLENT  
   Based on 170 reviews 
    
 
 
 
   
 
 
       Posted on Google  
   
   Katie Malone 
 
 
 
 Trustindex verifies that the original source of the review is Google. I went with a phobia and had such a lovely and warm experience with Jason. It was like going to a lovely spa experience or deep meditation class. I felt really relaxed & empowered after our session, thank you Jason! Would absolutely recommend.
  
 
      Posted on Google  
   
   claire malone 
 
 
 
 Trustindex verifies that the original source of the review is Google. Jason is great at what he does. He’s so easy to deal with too.. makes you feel very at ease. Highly recommend 🙌🏻
  
 
      Posted on Google  
   
   Darren Elliott 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had a brillant session today with jason and it has giving me so much clarity moving toward my goals that i can achieve anything i have my mind set on so thanks very much to Jason.
  
 
      Posted on Google  
   
   Orla Mc Donnell 
 
 
 
 Trustindex verifies that the original source of the review is Google. I honestly can’t recommend Jason enough! For over 10 years, I hadn’t tried any new foods because my mind would immediately tell me, “I don’t like that,” and I would feel sick at the thought of trying something different. I was extremely fussy — you could probably count everything I ate on two hands!

After just one session with Jason, something completely changed. He helped me realise that I could try new foods without that automatic negative reaction. Straight after the session, I ate a strawberry, a protein yoghurt and a Fulfil bar — all things I had never tried before — and I had absolutely zero issues. I just naturally tried them and realised that I actually liked two of them!

For someone who hadn’t tried a new food in over a decade, that feels absolutely huge. I’m so glad I decided to go to Jason. The difference after just one session has honestly amazed me.

Absolute 10/10 experience, and I would highly recommend him to anyone struggling with something similar. Thank you so much, Jason!
  
 
      Posted on Google  
   
   Kevin Shore 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had my first hypnosis session yesterday and was genuinely really impressed. I went in slightly sceptical and wondering whether hypnosis would actually work on me, but the experience was completely different to what I expected.

It’s quite difficult to describe, but I definitely reached an incredibly deep state of relaxation while still being aware of everything that was happening. I left the session feeling more relaxed than I have in a very long time.

This was only my first of six sessions, so I’m really interested to see how things progress from here, but based on my first experience I’d absolutely recommend giving it a try, particularly if, like me, you’re unsure whether hypnosis will work for you.
  
 
      Posted on Google  
   
   Mark D 
 
 
 
 Trustindex verifies that the original source of the review is Google. I found my first hypnotherapy session with Jason calming and relaxing. He fully explained the process beforehand which enabled me feel comfortable and at ease. Thank you Jason and I look forward to continuing.
  
 
      Posted on Google  
   
   Mark Keogh 
 
 
 
 Trustindex verifies that the original source of the review is Google. What can i say, was skeptical when i booked but even after the first session i could feel the differences, will definitely be back to work on some other issues.
  
 
      Posted on Google  
   
   Paula Kelly 
 
 
 
 Trustindex verifies that the original source of the review is Google. I had a really positive experience working with Jason. From the first session, he made me feel comfortable, less anxious & more relaxed.
The sessions were calm, professional and tailored to what I needed each session depending on the level of anxiety etc.
I’ve noticed a real improvement since starting and I feel more positive and equipped with the tools.
I wouldn’t hesitate to recommend Jason to anyone who is considering hypnotherapy and is looking for a welcoming supportive and professional approach.
  
 
      Posted on Google  
   
   Barry Walsh 
 
 
 
 Trustindex verifies that the original source of the review is Google. I've seen it all — the kind of things that harden you and make you think you can handle anything. But there was one deeply personal issue I'd carried for years that nothing else could touch. It affected my sleep, my focus, and my peace of mind in ways I couldn't fully explain.
Jason O'Callaghan is the real deal. Extremely professional, no-nonsense, and highly skilled, he created a safe space and used hypnosis and psychological techniques tailored to me. He helped me finally understand and resolve something that had been weighing me down for so long.
The difference is night and day. I feel clearer, lighter, and back in control. If you're carrying something heavy that conventional approaches haven't fixed, I highly recommend Jason. He's helped me more than I expected

Thank you Jason
  
 
      Posted on Google  
   
   Feargal Kelly 
 
 
 
 Trustindex verifies that the original source of the review is Google. I found Jason's sessions to be very helpful in managing stress levels and facing life challenges with greater resilience. I would have no hesitation in recommending his service to others. Many thanks.
  
 
  
  
 
    Verified by Trustindex  Trustindex verified that these reviews were published on D4 Clinic Hypnotherapy Dublin's Google Business Profile. Learn more

Dear Jason,

Many thanks for your help at D4 clinic. I have now lost over 3 stone and feel so good. This picture of me is in my first pair of size 12 jeans in over 20 years. It is just amazing how it has worked. I now love my daily walk.Thanks again for all your help. I would have no hesitation in recommending the D4 CLINIC to my friends and colleagues.

Breda Keating

"Hi Jason, how you doing. I am going great since we last spoke, down just 2 stone and finding I feel much better and have a lot more energy each day. Walking daily and listening to my stomach has made a lot of difference. My friend Kelly was recently in with you also after I told here about you and she is nearly down a stone already. So both of us are looking forward to a nice shopping spree soon. Thanks so much"

FLO - Dublin 6

“I found Jason O’Callaghan and the method of hypnosis very beneficial for weight loss. In 3 months, I lost 3 stone and am delighted. The thing I loved most about it was that it seemed to act behind the scenes in my mind and make the whole process quite easy and achievable.”

SAMMI - Dublin

Thanks all. Should have got the hypnosis done years ago. Flight was quite pleasant and hopefully will be the same on way back. Just shows the power of the mind. Thanks to d4 clinic and Jason O’Callaghan for making it happen for me. I would recommend a visit to Jason for anyone suffering a phobia to get it sorted once and for all.

Ciara - Dublin

46 year old Arlette started our program to lose over 3 stone and get back to her target weight so she could compete for Ireland in the world powerlifting championships this week. Congrats and good luck

Arlette

Mum of two Melissa (39) from Dundalk, Ireland has lost over 4 stone in six months with our VIP gastric band hypnotherapy program.

Melissa - Dundalk

About Jason O'Callaghan

Hello, I'm Jason O'Callaghan.
Member of the Psychology Society of Ireland
M.Ps.S.I. (Membership No M13886)

Since 2012, I’ve helped thousands of people across Ireland create lasting change through evidence-based clinical hypnotherapy, psychology, counselling, CBT and mindfulness. If you’re looking for a trusted hypnotherapist in Dublin to help with weight loss, smoking, anxiety, stress, confidence or unwanted habits, you’re in the right place.

Our programmes mix clinical hypnotherapy, counselling, CBT and mindfulness to address the root causes behind what’s holding you back — in person at our Blackrock clinic, through personalised hypnotherapy audio programmes, or via downloadable bundles you can use anytime.

Qualifications & Experience

Beyond the clinic

Before founding The D4 Clinic, Jason spent ten years as a journalist with The Sunday Independent, interviewing world leaders, public figures and high-profile personalities — skills that help him understand people quickly and communicate clearly.

He is also recognised as Ireland’s leading event stage hypnotist, and lives in Blackrock, Co. Dublin with his wife, three children and two dogs.

Although hypnotherapy results cannot be guaranteed, you can rely on Jason’s clinical experience, professionalism and commitment to helping you achieve the best possible outcome.

What I can do for you

Help you reduce anxiety, manage stress and feel more in control through personalised clinical hypnotherapy and psychological techniques
Break unwanted habits such as overeating, smoking, vaping or negative thinking patterns with structured, evidence-based strategies
Improve confidence, focus, sleep and emotional wellbeing using an approach grounded in psychology, CBT, mindfulness and counselling
Provide VIP intensive sessions for clients who want deeper support or faster results
Offer flexible options including in-clinic sessions, personalised hypnotherapy audio programmes and downloadable bundles

Ways The D4 Clinic Can Help

A complete range of hypnotherapy, counselling, mindfulness and CBT services — from in-clinic sessions and online appointments to VIP intensives and instant-access downloadable programmes.

View All Treatments

Stop Smoking Hypnotherapy

Weight Loss Hypnotherapy

€99 Bundle

Bumper Bundle

Anxiety Hypnotherapy

Blushing Hypnotherapy

Break Your Relationship with Food Hypnotherapy

Claustrophobia Hypnotherapy

Deep Sleep Hypnotherapy

Dentist Visit Anxiety Hypnotherapy

Fear of Clowns Hypnotherapy

Fear of Flying Hypnotherapy

Gambling Addiction Hypnotherapy

Instant Confidence Hypnotherapy

Junk Food Addiction Hypnotherapy

Nail Biting Hypnotherapy

Nicotine Gum Dependency Hypnotherapy

Procrastination Hypnotherapy

Public Speaking Hypnotherapy

Reduce Alcohol Habit Hypnotherapy

Social Anxiety Hypnotherapy

Stop Vaping Hypnotherapy

Stress and Anxiety Hypnotherapy

Sugar Dependancy Hypnotherapy

Three Simple Steps to Get Started

Step 1 – Get in Touch

Tell Jason what you’d like help with.

Step 2 – Discuss Your Options

Find out more about the available treatments and programmes.

Step 3 – Start Making Changes

Arrange an in-person appointment in Blackrock or discuss online options.

Support That Fits Your Life.

In-Person Hypnotherapy

One-to-one sessions at The D4 Clinic in Blackrock, with VIP intensive sessions available for deeper support.

Online Consultations

Personalised support from the comfort of your own home, wherever you are in Ireland.

Hypnotherapy Audio Programmes

Instant-access downloadable programmes, including the €99 Bundle and the Bumper Bundle, to use anytime.

Media coverage & credentials

Jason has appeared on ITV’s This Morning and in the Irish press, and spent ten years as a journalist with The Sunday Independent.

Together, we can create the change you’re ready for so you can feel calmer, clearer and more in control.

Ready to Make a Positive Change?

Whether you’re looking to lose weight, stop smoking or overcome something that’s holding you back, the first step is getting in touch.

Find out how Jason may be able to help.