You can buy vitamins and supplements from US retailers such as iHerb, dōTERRA, Amazon, Vitacost, Swanson and The Vitamin Shoppe, as well as directly from manufacturers. There are two ways to shop through UNDbox: place and pay for the order yourself, or ask us to buy it for you. The retailer ships your order to your UNDbox warehouse address in the US. Once it arrives, you can arrange delivery to your city.
This guide covers where to find products, how to read the label and how to work out the cost, including shipping. Store screenshots and warehouse photos show which details to look for and what you can check before your order ships.
Contents
- Where to buy vitamins and supplements in the US
- Best US vitamin brands: survey rankings
- iHerb vitamin and supplement bestsellers
- NOW, Solgar and Centrum: how to compare products
- How to read a supplement label
- How to order vitamins from the US
- What you can check at the UNDbox warehouse
- Frequently asked questions
Where to buy vitamins and supplements in the US
Search the store by brand, full product name or both. If you have bought the product before and know its item number or UPC barcode number, you can search by that instead.
| Store | What to know |
|---|---|
| iHerb | Sells its own brands, including California Gold Nutrition, alongside other manufacturers' products. Product pages let you choose a package size and view the price per serving. Heavily discounted items may be close to their expiration date. |
| Amazon.com | You can order vitamins from several brands in one Amazon checkout. Prices and domestic US shipping depend on the seller, whose name appears under Sold by. |
| Walmart | The catalog includes Spring Valley, Equate, Nature Made, Centrum and other brands. Walmart.com also has third-party sellers. The product page identifies who sells and ships the item. |
| Vitacost | Stocks NOW, Jarrow Formulas, Life Extension and other brands, as well as its own Vitacost range. According to the store's service update, iHerb fulfills its orders, so a Vitacost purchase may arrive in an iHerb box. |
| Swanson | Buy Swanson supplements directly from the brand or compare them with other brands on the same site. If you plan to use Wellness Rewards, note that the program is available only to US residents. |
| The Vitamin Shoppe | Sells its own The Vitamin Shoppe and Vthrive brands. For repeat orders, it offers Auto Delivery: the published terms list 20% off these two brands and 15% off most other products. These are subscription discounts, not one-time purchase prices. |
| NOW | An option for buying directly from the brand, with different package sizes available. Some other brands do not sell directly on their websites. Instead, a Where to Buy button links to retailers such as iHerb or Amazon. |
| dōTERRA | The brand's official website lets you order supplements directly. The catalog shows two prices: Retail for regular purchases and Wholesale for program members. According to dōTERRA, you can buy at retail prices without joining the program. |
| Life Extension | The manufacturer's own store lets you buy Life Extension supplements directly and browse a bestsellers section. For some offers, the final price appears only after you add the item to your cart or sign in. |
| Thorne | Thorne's official store lets you filter products by ingredient and form, including capsules, liquids, powders and tablets. For repeat purchases, it offers a subscription: 10% off subscriptions for 1-2 supplements and 20% off 3 or more. Exceptions apply to bundles and wholesale accounts. |
| GNC | A US retail chain with its own Mega Men and Women's Ultra Mega ranges, alongside other brands. The site distinguishes regular promotions from PRO member offers, so the member price may differ from the regular price. |
If you are looking for alternatives to iHerb, start with the stores in the table. Choose two or three sites and compare the same package. No single store is always cheapest for every supplement: the total depends on the product price, discounts and domestic US shipping.
What to check on Amazon
Different companies may sell the same supplement on Amazon. On the product page, find Sold by, which identifies the seller. Click the name to see company details and customer feedback about its orders. These seller ratings are separate from the product reviews below the supplement's title. Buy vitamins only from highly rated sellers.
The Ships from field identifies who ships the order. Ships from Amazon / Sold by another company means Amazon stores and ships a third-party seller's product. Before adding it to your cart, compare the number of capsules per bottle and the number of bottles included.
If the listing says Ships from Amazon / Sold by Amazon, you can buy with confidence: these are genuine, verified vitamins.
In the screenshot below, Sold by lists Carlyle, while Ships from lists Amazon. Carlyle is the seller of this supplement, and Amazon handles shipping. Click the seller's name in that line to view its details.
How to avoid signing up for a subscription by mistake
Subscribe & Save, Subscribe to Save and Auto Delivery mean recurring orders on a schedule. The price beside these options may be lower than the one-time purchase price. If you do not want a subscription, select One-time purchase. Before paying, check that your order does not include recurring deliveries.
Best US vitamin brands: which ones lead the rankings?
Pharmacy Times lists the following results in its Multivitamins category:
| Rank | Brand | Share of survey responses |
|---|---|---|
| 1 | Centrum | 33% |
| 2 | One A Day | 27% |
| 3 | Nature Made | 22% |
These results come from a survey asking pharmacists which brands they recommend. The percentages do not measure effectiveness or market share. Source: Pharmacy Times, Multivitamins category.
US supplement brands ranked by customer satisfaction
ConsumerLab's 2026 survey collected more than 8,850 responses from vitamin and supplement users. The following brands had the highest overall customer satisfaction in their respective categories:
| Brand | Category led |
|---|---|
| Life Extension | Catalog and internet brands; also the multivitamin category |
| Nature Made | Broadline brands sold in pharmacies and mass-market stores |
| Kirkland Signature | Discount and warehouse club brands, including Costco |
| dōTERRA | Direct-selling brands |
| The Vitamin Shoppe | Vitamin store brands |
Each row represents the winner of a separate category. These are customer ratings, not laboratory comparisons of every product sold by these companies. Source: ConsumerLab, 2026 survey results.
To start exploring the leading multivitamin brands in these surveys, look at Centrum, One A Day, Nature Made and Life Extension. If you have already chosen a supplement, search for its full name. A brand's ranking does not mean all its products have the same ingredients.
Which vitamins and supplements are popular on iHerb?
In its Best Sellers section, iHerb lists popular products based on sales over the past 24 hours. The list updates daily. At the time of review, it included the following supplements:
| Product | Package size |
|---|---|
| NOW Foods Magnesium Glycinate | 180 tablets |
| Doctor’s Best High Absorption Magnesium Lysinate Glycinate | 240 tablets |
| Life Extension BioActive Complete B-Complex | 60 vegetarian capsules |
| NOW Foods Vitamin D3 & K2 | 120 capsules |
| California Gold Nutrition Omega-3 Premium Fish Oil | 100 fish gelatin softgels |
NOW, Solgar, Centrum and other brands: how to compare products
NOW vitamins and supplements can be found on the manufacturer's website and compared with retailers' listings. The same supplement may come in several bottle sizes. For an exact comparison, find the UPC number beneath the barcode. It helps distinguish packages with similar names.
Solgar vitamins and supplements are listed under the Solgar brand name. On the brand's website, you can check the product name and label, then find the same item at a retailer. Products from the same brand do not necessarily have the same ingredients.
Centrum vitamins come in several versions. On the brand's US website, find the full name of the multivitamin you want and compare it with the retailer's listing. Check the form and number of tablets or capsules in the bottle.
Check whether the label says tablets, capsules, softgels or gummies. These are different product forms. Do not swap capsules for gummies simply because their names sound similar: their formulas may differ.
How to read a US supplement label before ordering
The iHerb screenshots show California Gold Nutrition Omega-3 Premium Fish Oil, in a bottle of 100 softgels. The first shows the front label; the second shows the back label selected in the image gallery. This lets you check the package and ingredients before buying.
| Label term | What it means |
|---|---|
| Supplement Facts | The panel listing ingredients and their amounts per serving |
| Serving Size | The size of one serving, such as two softgels |
| Servings Per Container | The number of servings in the bottle |
| Amount Per Serving | The amount of an ingredient in one serving |
| Other Ingredients | Additional ingredients, such as capsule shell materials, fillers and flavorings |
| Expiration / Best By / Best if Used By | Wording beside the date printed on the package |
| Lot / Batch | The production lot or batch number |
The bottle shown contains 100 softgels. Serving Size - 2 softgels, so it provides 50 servings. Check this line even when buying a familiar brand: the same capsule count does not always mean the same number of servings.
The screenshot shows a bottle price of $12.20. Divide that by 50 servings to get $0.244, or about $0.24 per serving. This calculation uses the offer shown and excludes shipping. Check the current price in your cart before buying.
The front label lists 180 mg of EPA and 120 mg of DHA per softgel. The Supplement Facts panel lists 360 mg and 240 mg for two softgels. There is no discrepancy: the panel gives amounts per full serving. Read Serving Size first, then compare the numbers. These labeling rules are explained in the FDA's guide.
Pay attention to units too: mg means milligrams, and mcg means micrograms. They are different units. Under Other Ingredients, check the capsule shell materials and any additional ingredients. If the text is hard to read, enlarge the image or find the label on the manufacturer's website.
How to compare the same supplement at two stores
First, make sure you are looking at the same product: match the name, item number or UPC, ingredients, form and capsule count. Check whether the offer is for one bottle or a multipack. Then look at Servings Per Container. Price per serving = bottle price ÷ number of servings. This helps compare costs, not health benefits. The serving size on the label is not necessarily the amount you personally should take.
Add the product to your cart at each store, enter your warehouse address and check the total after discounts and domestic US shipping.
How to order vitamins from the US through UNDbox
1. Choose your product and how to buy it
You can buy vitamins and supplements from the US yourself or submit a purchase request to UNDbox. If you order yourself, you pay the retailer directly. With our assisted purchase service, we place the order using your product link.
In your purchase request, include the exact product name, package size and number of bottles. If the listing has several options, select the one you want. You can also add: “No substitutions. If this option is unavailable, please contact me.” This prevents a different size or formula from being bought without your approval.
2. Ship your purchase to the warehouse
To place an order yourself, use the warehouse address in your UNDbox account. Enter it at checkout. After paying, save your order confirmation and add the tracking number to your account.
With UNDbox's assisted purchase service, we arrange the purchase and delivery to the warehouse. You will see the service fee and other purchase costs before paying for your request. International shipping is charged separately, after the goods arrive at the warehouse and are prepared for dispatch.
3. Request photos and packaging if needed
Once your order arrives, you can request photos to check the number of bottles and their expiration dates. If you are waiting for other purchases, you can combine them in one parcel. Before packing, decide which items to ship together and whether glass bottles or containers need extra protection.
Read the storage instructions on the label. A regular cardboard box does not provide refrigerated shipping for a product that requires it. Gummies can stick together in hot weather. If your supplement has these requirements, discuss packaging and shipping before buying.
4. Arrange delivery to your home
In your UNDbox account, select the purchases that have arrived and your shipping method, enter the recipient's details and submit the parcel for packing. For an estimate, use the shipping calculator. The final cost will be available once the parcel has been packed and weighed.
How to order vitamins from iHerb
- Open the iHerb catalog and browse the vitamins or supplements section. You can find products through categories, filters, the brand directory or search.
- Choose the package size and number of bottles, then add them to your cart.
- Enter the warehouse address shown in your UNDbox account and pay for your order.
- Once iHerb ships your purchase, add the tracking number to your UNDbox account.
- When it reaches the warehouse, arrange shipping to your home. You can first request product photos or combine the purchase with orders from other stores.
If you need help paying, submit a purchase request through UNDbox. Include the product link, package size and quantity.
Real UNDbox warehouse photos: what you can check before shipping
The UNDbox warehouse photo below shows Young Living Sulfurzyme, Whole Body Cleanse, ImmuPro and LiverTone. A photo like this lets you check product names and count the packages. If you ordered several different supplements, a group photo helps confirm that they have all arrived.
The other image shows three bottles of dōTERRA EO Mega+, each containing 90 softgels, along with the markings on their bases. The front labels identify the product; the view from below shows the date next to EXP and the batch code.
Request warehouse photos and an item check and specify the view you need. To check the expiration date, ask for a close-up of the date. To confirm the product, ask for the name and capsule count. These services are available on request.
| What to request from the warehouse | What the photo shows |
|---|---|
| A close-up of the label | Product name, capsule count, ingredients and serving size |
| A photo of the date and batch number | The markings on the bottle that arrived |
| A photo of the cap and outer seal | The condition of any protective wrap or tamper-evident ring |
| A group photo of the bottles | The number of packages and product names |
| A photo of any damage | Cracks, dents, leaks or other visible damage |
If you have several bottles, you can request a photo of each one. If a marking is hard to read, ask for another angle. Do not try to decode a batch number using a similar product you found online.
Bottles are not opened for photos. Protective wrap and tamper-evident rings need a close-up: a general view of a closed cap is not enough to assess their condition.
Frequently asked questions
Where can I buy US supplements besides iHerb?
You can buy them from Vitacost, Swanson, The Vitamin Shoppe, Amazon or the manufacturer's own website.
Can I buy vitamins on Amazon?
Yes, Amazon sells vitamins and supplements. The main difference from a regular online store is that the same product listing may include offers from several sellers.
How can I check the expiration date after buying?
Check the retailer's product page, ask its customer support team or request a photo of the date on your bottle once it reaches the warehouse.
Can I combine vitamins with other purchases?
Yes. You can combine vitamins and supplements with purchases from other stores at the UNDbox warehouse in the US and receive everything in one box.