Brenda P.
ZCALM
Awesome service and best products!!
Reply from Z-STACKMar 10, 2026
Thank you!!

Great
Based on 95 reviews
Honesty, pricing, process and quality scores appear once 5 customers have rated them.
Zelenko Labs, built on the legacy of Dr. Vladimir Zelenko, creates products with purpose, precision, and integrity. Every formulation is made with high-quality ingredients and consistent standards, so you can feel confident in what you’re using. Thoughtful, reliable, and principled — Zelenko Labs products are made for people who care about quality.Our All American customer service team is here to help Monday through Friday, 9 AM to 5 PM EST — just give us a call at 1-800-ZELENKO (1-800-935-3656) or email our team at [email protected]
Z-STACK (zstacklife.com) has 95 customer reviews on Folks Told, with an average rating of 4.1 out of 5.
Showing 71 reviews with 5 stars · Clear filters
Brenda P.
Awesome service and best products!!
Reply from Z-STACKMar 10, 2026
Thank you!!
Carolyn C.
I have been using Zflu since Dr.Zelensky developed it. Zflu has all the vitamins/minerals needed to prevent and or treat the flu, without having to spend all the money on each of the vitamins separately. I even have my grandson taking Kids Zflu and have recommended it to all my friends. Zflu keeps us symptom-free all year long!!!
Reply from Z-STACKMar 2, 2026
I LOVE TO HEAR IT!!!!
Rose G.
Dr Zalenko's products are top of the line; my husband and I have been on them since the onset. We have also shared them with family and friends for them to try. We feel our immune system has gotten stronger since we first started with Z-stack and now on Z-detox. I will continue to promote them on facebook and instagram as well because I trust this for everyone.
Reply from Z-STACKFeb 27, 2026
Thank you!
Natalia Stankova S.
At first I couldn’t understand what you were trying to tell me, but then did. All messages were in a calm and friendly tone. Thank you very much for your attention and support.
Reply from Z-STACKFeb 27, 2026
Thank you! The team appreciates you!
lisa M.
I had not gotten my order after 2 weeks time. I was sent a replacement right away. Thank you! Also, this product-Z-Stack has been fantastic in maintaining immune system. I have been taking it for years and have not gotten sick for a long time. No yearly cold or flu like many acquaintances. Highly recommended.
Reply from Z-STACKFeb 24, 2026
Always a pleasure Lisa!
Linda T.
I am very fortunate to have found Dr Zelenko’s vitamins. At 80 years old, I have been able to stay well and have not suffered even one Covid event. I attribute my good health to Dr. Zelenko’s vitamins.
Reply from Z-STACKFeb 16, 2026
Thank you Linda!
Pam
I had a fast and great response to my issue that was quickly resolved. I am so thankful! Pam
Reply from Z-STACKFeb 8, 2026
Thank you Pam! Have a wonderful week!
G
I get the kids gummies for my children and end up stealing some for myself
Reply from Z-STACKFeb 5, 2026
We are so glad to hear!