Page 1 - Reviews - 21st Century, B-100 Complex, Prolonged Release, 60 Tablets - iHerb
Your preference has been updated for this session. To permanently change your account setting, go to My Account
As a reminder, you can update you preferred country or language anytime in My Account
> beauty2 heart-circle sports-fitness food-nutrition herbs-supplements pageview
Click to view our Accessibility Statement
}
Free delivery over NZ$110.00
checkoutarrow
Supplements
Sports
Bath & Personal Care
Beauty
Grocery
Home
Baby & Kids
Pets
Brands A–Z
Health Goals
Deals
Bestsellers
Try
New
Wellness Hub

Customer Ratings & Reviews

100% authenticOur products are sourced directly from brands or authorised distributors.Show more
4.7
Based on 4,971 ratings
3,928
740
222
43
38
Write a review
What customers say
(454)
 
Rating

Rating

Languages
English (UK)
Languages
Show auto-translated reviews(454)
Show reviews with images only
Review images
English (UK)
Translated reviews
SandBlaster
Posted on 18/08/2025
South Korea
39
56
0
28
Good for recovering from fatigue
Verified Purchase
I was taking the 50mg version, but it was sold out, so I ordered the 100mg version. Since it's twice the strength, will it be twice as effective? It's a bit large. Taking one vitamin B complex pill a day helps relieve fatigue and makes me feel more energetic.
Auto-translated from Korean
09326122-aa6d-4f26-ab0b-3f80d68beffd
7dc0535e-caa9-4a04-8dfb-6d385504e9ea
iHerbCustomer
Posted on 26/11/2025
Ukraine
21
9
0
3
Verified Purchase
Very good complex of B vitamins. Significantly increases energy and concentration. I liked the slow release - no sharp peaks and drops. The tablet is swallowed normally. The effect is mild, without side effects.
Auto-translated from Ukrainian
Yuliya
Posted on 13/10/2025
United States
36
0
0
0
Fine
Verified Purchase
I'm an athlete, so I chose these vitamins for the quality of the ingredients, the package size, and the presence of folic acid. The results were excellent.
Auto-translated from Russian
iHerbCustomer
Gold
Posted on 15/06/2026
Kuwait
847
1
13
24
Verified Purchase
Energy Boost Vitamin Supplement, Gluten-Free, GMO-Free, Lab Tested - Quality Guaranteed, Trusted Quality for Over 30 Years. The B vitamins are interdependent and their functions overlap; they help convert food into energy and maintain the health of the nervous system and body tissues. Extended-release vitamins release nutrients slowly into the body over a prolonged period.
Auto-translated from Arabic
yuyu
Posted on 21/05/2026
Japan
51
0
0
1
I found out through genetic testing that I was deficient.
Verified Purchase
I had a genetic test and found out I was deficient in vitamin B, so I started taking it. I feel like I'm experiencing less dizziness!
Auto-translated from Japanese
iHerbCustomer
Posted on 6/02/2026
France
61
6
2
13
Прекрасно!
Verified Purchase
Quality is super! The ingredients are great! Size arranged! What you need! Performance is felt! the product arranged, perfectly packed, the effect is definitely there! I will order more! Just as quickly delivered
Auto-translated from English
iHerbCustomer
Silver
Posted on 4/12/2025
Japan
254
0
0
86
Verified Purchase
I love sweet things, so vitamin B1 is a must-have. This is cheap and helpful!
Auto-translated from Japanese
iHerbCustomer
Silver
Posted on 30/07/2025
Armenia
285
0
0
2
Verified Purchase
I like this product. I will buy more. Energy increases. Quality
Auto-translated from Russian
iHerbCustomer
Silver
Posted on 29/07/2025
Hong Kong
140
0
0
2
Verified Purchase
High Quality of B Complex,good size,it helps me removes muscke stiffness
Auto-translated from English
Tetiana
Gold
Posted on 6/05/2026
Ukraine
397
9
1
252
The forms here are mostly inactive and budget-friendly.
Verified Purchase
A good basic complex for its price, especially if you need support for the nervous system, energy and metabolic function. The slow-release format can be convenient for a more even intake of B vitamins throughout the day. But the dosages here are quite high, especially B6, so I would not choose it for constant long-term use without indications. It is better to take courses or with increased needs, stress, fatigue, intense loads. For its price, it is a working option, but for sensitive people or with problems with methylation, active forms of B vitamins are often better suited.
Auto-translated from Ukrainian