Z-STACK Avis 

Kindness expressed
Willingness to pause delivery schedule

Great customer service! Quick to respond and very helpful. I absolutely LOVE the Zstack. I don’t want to ever be without it.

I had an order "swap products" question this weekend and sent off an email asking how to do it! Well, I figured it out myself, made the swap, it was a quite easy actually. There was an email from the Z-stack customer service department in my inbox this morning, that was quick! We went over the details of my account and order, all was well. Been with Dr Zelenko for several years now, great products, great company!

Choosing some of my supplements from Z stack may have been one of the best choices I made in years for my health. The vitamins I choose to use are the z stack with vitamin c, d, zinc and quercetin. Prior to these vitamins, I would take just vitamin c and d. I have learned so much from Dr Zelenko during the COVID times, I really didn’t trust many drs at the time but he was true to his word, may he Rest in Peace. This company is legit if you want your immune system working well, in my opinion, the company works with you and the delivery is pretty fast. I really do appreciate this company still existing and I pray they continue.

I have been taking this for many years in fact since it came out. I have not gotten sick and I truly believe it is because I take this every day. I have it on auto ship so I am never with out it.

This company is always there to help whether it’s adding a bottle or skip a month. Thank you for your outstanding service

Customer service is everything !!! I credit Zelenko for providing courteous, timely, professional customer service from start to finish. The product is #1 in my experience during COVID epidemic. I continue using the product faithfully. Opting -out from taking the vaccination was 100% due to my faith in GOD and the product living up to its' claims to strengthen my immune system ! To date, I have not been disappointed and commend Dr. Zelenko for developing his outstanding formula. GOD bless him!

Thank you so much for the quick response, for the product that is beneficial for our health, and for your help also on sending us the vitamins to our current address. We truly appreciate it and value your business.

This is my first year since Covid to be and feel healthy even during flue season. The Zelinco Protocol is a wonderful solution for rebuilding your immune system.

I started taking Z Stack shortly after COVID hit. Haven't been sick. Yes, I didn't get COVID either. My immune system is thanking me.
I also have started (a few months ago) talking CALM. It's enhanced my use of St Johns' Wort and a prescription med for anxiety.
I would recommend both supplements to anyone asking about them.

I’ve been using Z stack for going on six years ever since Covid started and it has been my go to immune booster. I use the Z night now to get a restful sleep and they Zelin go laps is my trust is Source for health protection.

A+ product and excellent customer service. I highly recommend Zelenko Labs.

Zstack is the best supplement my husband and I have had so far. We’ve never been sick since we started to use it. It has every ingredient in it that our body needs. Unfortunately we’re paying a postage as high as for one bottle of Zstack. This is the only reason we have to stop buying it. For this reason being said we’re not happy that nothing can be done in that direction. Although we would recommend Zstack to anyone.

I have had a subscription for Z-Stack for over 4 years. After covid I was looking for a good vitamin. I knew I was low in Vitamin D, and I wanted a vitamin that would help with my low Vitamin D levels. I started listening to Dr. Zelenko and decided to try the Z-Stack. After taking Z-Stack for several months, I had bloodwork done and my Vitamin D levels were better than they ever have been and continue to be at a healthy level every year and that is why I continue my subscription each year. The vitamins work. I am confident these vitamins help me stay healthy. You will not be disappointed with these vitamins.

Our family has been using Zelenko products since their inception. My grands especially like the strawberry flavored gummies now ZFlu. Thank you for keeping Dr. Zelenko’s legacy alive and well!

I have been using your products for years. Very happy with the product and services received.

Awesome service and best products!!

I use Z Stack & it really helps. Haven’t been sick in over 5 years. I did cancel Z Night because I saw no benefit to me after 2 years.
Over all been quite satisfied. The support staff have been very helpful and supportive.

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!!!