Z-STACKZelenko 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 Five Star Index, with an average rating of 4.1 out of 5.
Is this your business?
Correct your details and reply to customers in public. Both are free.
Claim this listing
Personal Care · Orlando, Florida
Excellent
Personal Care · Grants Pass, Oregon
Excellent
Personal Care · Great Neck, NY
Excellent
Personal Care · Costa Mesa, California
Excellent
95 approved reviews, newest moderated first
Rosario
I have been taking Z-Stack for several years now, and I haven’t been sick since—not even with a cold. My immune system is very well protected. I am writing from Peru, and I hope to be able to purchase this product again soon. Thank you.
Response from Z-STACKOct 21, 2026
Thank you Rosario!
david
When I take these supplements I don't get sick especially a cold and of course COVID. Dr Z was recognized for his research in fighting COVID and developed Z Stack that actually ALLOWS the zinc to be absorbed thereby KILLING the cold virus. These are the best you can get when it comes to upping the immune system.
Response from Z-STACKOct 20, 2026
Thank you David!
Tammy F. Brooklyn, N.
Zalanko Labs has excellent products and customer service. I really appreciate the wya they handle orders promptly and efficiently and get back to me immediately.
Response from Z-STACKOct 8, 2026
Thank you!
Lisa
Disappointed that the order default is automatically on SUBSCRIPTION. You have to OPT into a 1 time order. Feels deceptive and only way to correct it is by contacting the co. You can't correct online.
Response from Z-STACKOct 7, 2026
This is incorrect. Please see our Youtube videos on how to Login and Manage your Subscription: https://www.youtube.com/@zstackofficial
Sandra
My husband and I have taken Z-Stack since the beginning of covid. Neither of us ever contracted covid nor have either of us have had a cold since beginning Z-Stack.
HAPPY C.
The support team answered and resolved my query very quickly. They were caring in their words when answering and I felt valued as their customer. Thank you support.
Response from Z-STACKSep 28, 2026
Thank you :)
Saundra C.
I have been using Z Labs products since covid. I'm hardly ever ill. My husband and I started with Z Stack and he takes it every day. I use Z Flu gummies, Z Calm and Z Night. I highly recommend them for good health!
Dawn H.
Zstack has the best products and customer service! Prompt reply’s, and kind folks behind the messages. I’ve been using Zstack for a handful of years now and I’m so impressed by the innovation of their products and the quality ingredients! Highly recommend!!
Response from Z-STACKSep 22, 2026
Thank you Dawn! :)