Z-STACK Recensioni 

I started taking Z Stack as part of Dr. Zelenko's prophylactic Covid protocol, as soon as it became available. I am unvaxxed, did NOT get Covid and did not get any flu or respiratory infection. I'll take these as long as they are available.

Not sure what is going on with this company, but it is not good. After I placed an order for 2 bottles of Z-Flu on 04/30/25, they sent an e-mail on 05/08/25 saying..."We’re reaching out with an important update about your recent order for Z-Flu.Due to an unexpected backorder, we’re currently unable to ship your Z-Flu bottle as scheduled. We sincerely apologize for the inconvenience and are working hard to resolve the issue as quickly as possible". I have sent NUMEROUS e-mails telling them to refund my money to my credit card. Today is 05/15/25 and they have still not refunded my money! This is not the first time this company has not fulfilled my order, but I thought I'd give them one last try. NEVER AGAIN! BUYER BEWARE!

Does anyone else's Zstack smell/taste like stink bugs? I've been getting this product for years and it never smelled like this! I've actually gotten sick/upset stomach, so have to stop taking it.
I too, have had issues with getting my purchases timely and noticed that you cannot remove/delete credit cards that you put on file. I've referred family & friends to this product but no more!

I’ve been using Z-stack and Z-Flu for 3-4 years now and liked it. From my experience their customer service has become horrendous! In the past you could speak with a real person. Not anymore. It’s all automated via email only. I’m still waiting on an order from their Black Friday sale November 28th! Another two orders from December and January also. They keep saying “shipping tracking numbers going out this week.” But it never happens. Right now I’m out nearly $160 and I have a bad feeling they are blowing me off. If I ever get my order, I will not purchase anymore. I use to recommend their products, but now I’m embarrassed that I did. Use caution when ordering.

I've been taking 2/daily Z-Stack (monthly auto-ship) since hearing Dr Zelenko speak several years ago. I am a frail 85# 75 yr old with advanced COPD/Bronchitis that has not had so much as a cold or a flair-up since & still going strong. Prior, I would have 3-4 severe, lengthy flair-ups annually. It's been a blessing for me.

Absolutely horrible service

I have been charged twice and not received my kid's vitamins. They charged me once for an order I didn't place. I received a terrible quality product in the summer months that looked like it had melted during shipping. Definitely do NOT do business with this company.

Good products but their customer service is the absolute worst!

We received kids products that were not as advertised nor what we had received in prior orders. I asked for replacement products to be sent. They want me to pack up the products received, mail them back and pay for the shipping! Totally ridiculous!

Not how you run a successful business and want to keep returning customers!

Customer service is the worst. The label was created, but never received by the post office. When I got Larry on the phone, he blamed the post office. No response to emails. I will notify my credit card company to get my money back. Do not do business with this company! They simply do not care and probably over priced?

ordered a bottle, but there's no order confirmation and ship tracking. nothing happened except a ad email regarding next purchase. it's been a week and i still get nothing.

i would avoid this site forever and don't order anything from there!

I had been purchasing various supplements from Zstack. They were my go to and I trusted this company. My most recent purchase (a few months ago) included the kid's gummy supplements along with my usual order. The regular order was fulfilled with the exception of the kid's gummies. Initially, I did receive a mass email that explained issues getting the gummies out but they had a fulfillment date. With that, I decided to order more gummies to stay ahead of future issues. That fulfillment date passed a while ago and I've contacted them twice with no response. If they ever fulfill my orders, I will cancel my account with them. For now, my trust in them is gone and I will never buy another product from them again. Receiving no response to my concerns is not acceptable.

I have been using zstack since it came out. Me, who is prone to bronchitis, colds and always sick have not been sick since I began. I recently ran out and I didn't reorder because I found out I am loosing my job in July to outsourcing to another country 😪 anyway I wasn't taking it for about 2 ,3 weeks and I got the worse upper respiratory infection and bronchitis that I have ever had. It is 11 days and I am only maybe 70 percent. Well I am now ordering my supply. I'll save money elsewhere, these are too precious!! God bless Dr Z and his team. May he RIP

I was very disappointed with the Z stack vitamins. I bought it because I was specifically looking for an all-in-one combination, which this pill provided. However, everytime I take it I seem to have some sort of allergic reaction like runny eyes watery nose congestion. So, I'm not sure if there are additional ingredients in it that are causing me to have the allergy. I seem to do better when I just take the individual vitamins separately. Unfortunately, the z-stack did not work for me as I had hoped.

I am trying to cancel a reoccurring order but am unable to online. I have emailed at least 3 times with no response. 1 month later, i received a reply.

Can't really rate it, never received it. Made several inquiries since 9 Nov 2021 when I ordered a bottle. Received responses, bogus tracking numbers, and a claim from them they sent it on 3 day expedited delivery. NEVER RECEIVED IT!
TERRIBLE COMPANY to do business with. Be warned!!

Ordered 2 bottles on 9/27/2021, still have not received them. have sent multiple messages to them and no reply. just a scam company. reporting them to several agency's. asked them to return my messages and was ignored.

I had just posted that I didn’t receive my zstack but just deleted it because I received it today. It took a little over a month. I was upset because nobody returns calls
And we kept getting emails to order more.
Anyway will start taking them tomorrow! I’ve already had covid but wanted to continue to take the supplements to keep my immunity up!

I payed on a credit card I rarely use and after there were $2000 worth of fraud that occurred after my legit order with this company. Is this a scam going on? My credit card company took care of the fraudulent charges and sent me a new card. My order for a few bottles of Z-stack placed on Sept. 30th then I received an email on October 8th saying product was in the mail and now on October 28th product still has not been received. I have called the credit card company to dispute this charge.

I finally did receive the product after 23 days. Of course I tried calling and emailing with no response. Supposedly they were waiting for a shipment to come in. There was no action till I contacted PayPal about the purchase. Then my item was shipped the next day. I don’t know about the quality yet but I know it comes highly recommended. I will give it a chance.
I want to add that I did receive the product and was sent an extra bottle. I’m going to give them another try. It certainly is easier taking it and only two pills rather than six or eight.

I ordered a product (order 12085) from them on 2nd September for posting to Australia. For some reason it did not leave USA but was returned to them by US Postal Service on 20th September.
I have sent 4 emails, left a message on their website and never received one reply.
In frustration I rang them on 4th October (3rd Oct US time) and they promised to re-post to me and let me know the new Tracking details by 7th October, still no advice received as at 10th Oct. They may have a good product but their customer relations service is non existent.