diphenhydramine
Skip itA concentrated shelf (top 5 take 100% of clicks) — this niche doesn't clear our bar today.
Returns
Incredible0.0%return rate — above 5% kills the launch gate
Conversion
Incredible16.1%search→purchase rate — share of searches ending in a sale
Growth
Okay+16.8%90-day search growth — must beat 0% to launch
Market size
Okay£200K£200K/yr · 244K searches
Review moat
Bad4,080.4avg incumbent reviews — the moat a new listing must climb
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Avg price
Bad£5.09avg listing price — sweet spot $15–$100
Competition
Bad100%top-5 click share — a locked-up shelf
Brand share
Bad100%top-5 brand share — brand-locked demand
Price range
Bad£3.89–£6.76cheapest to priciest tracked listing — scored on the share inside $15–$100
According to Flapen's Amazon United Kingdom niche tracking, diphenhydramine is a £200K/yr Amazon United Kingdom market (244K searches/yr). The top 5 brands hold 100% of demand. Verdict: Skip it — 36/100.
Data updated Jul 24, 2026 · scored weekly · How we score niches
diphenhydramine market data
- Units sold / yr
- 30K–40K
- avg 6,000–8,000/product
- Revenue / yr
- £153K–£204K
- units × avg price
- Conversion rate
- 16.1%
- Avg BSR
- #13
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 80%
- Out of stock
- 0.0%
- Avg brand age
- 52 months
- Avg seller age
- 172 days
Competition & brand share
The top 5 products capture 100% of clicks — a locked-up shelf that new listings rarely crack.Brands
2 falling
Sellers
82
Top-5 brand share
100%
Top 20: 100%
Top-5 click share
100%
Top 20: 100%
Open market
0%
- Benadryl96%
- Crescent Pharma Limited4%
Demand
Weekly Amazon search volume, last 34 weeks — +16.8% search growth over the last 90 days.Top diphenhydramine search terms
- benadryl97K/yr
- benadryl allergy relief51K/yr
- diphenhydramine38K/yr
- benadryl one a day 30 tablets11K/yr
- diphenhydramine hydrochloride13K/yr
- acrivastine8K/yr
- benadryl for dogs17K/yr
- benedryl3K/yr
- diphenhydramine antihistamine2K/yr
- diphenhydramine tablets3K/yr
Top diphenhydramine products on Amazon
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 5 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Benadryl Allergy Relief Capsules (1 x 24) Antihistamine Capsules with Acrivastine Hayfever Tablets for Relief Suitable for Pet Dust and Skin Allergies
Benadryl£5.504.6★5,012 rev
Benadryl Allergy One A Day 10 Mg Tablets - Effective and Long-Lasting Relief - 30 Count
Benadryl£6.764.6★8,541 rev
Benadryl Allergy Relief Capsules (1 x 12 Capsules) Antihistamine Tablets with Acrivastine
Benadryl£3.894.7★2,778 rev
Benadryl Allergy Relief for Children 6+ Years (1 x 60ml) Tutti Frutti Flavour Syrup Sugar & Colour Free with Cetirizine Long-Lasting All-Day Relief
Benadryl£4.434.7★390 rev
240 x 10mg Cetirizine Dihydrochloride (8 Months Supply) One a Day hay Fever and Allergy Relief Tablets (8x30 Tablets)
Crescent Pharma Limited£4.854.8★3,681 rev
Newest
by launch dateBenadryl Allergy Relief for Children 6+ Years (1 x 60ml) Tutti Frutti Flavour Syrup Sugar & Colour Free with Cetirizine Long-Lasting All-Day Relief
Benadryl£4.43390 rev
240 x 10mg Cetirizine Dihydrochloride (8 Months Supply) One a Day hay Fever and Allergy Relief Tablets (8x30 Tablets)
Crescent Pharma Limited£4.853,681 rev
Benadryl Allergy Relief Capsules (1 x 24) Antihistamine Capsules with Acrivastine Hayfever Tablets for Relief Suitable for Pet Dust and Skin Allergies
Benadryl£5.505,012 rev
Benadryl Allergy One A Day 10 Mg Tablets - Effective and Long-Lasting Relief - 30 Count
Benadryl£6.768,541 rev
Benadryl Allergy Relief Capsules (1 x 12 Capsules) Antihistamine Tablets with Acrivastine
Benadryl£3.892,778 rev
Trending
90-day click momentumBenadryl Allergy Relief for Children 6+ Years (1 x 60ml) Tutti Frutti Flavour Syrup Sugar & Colour Free with Cetirizine Long-Lasting All-Day Relief
Benadryl£4.434.7★
Benadryl Allergy One A Day 10 Mg Tablets - Effective and Long-Lasting Relief - 30 Count
Benadryl£6.764.6★
Benadryl Allergy Relief Capsules (1 x 12 Capsules) Antihistamine Tablets with Acrivastine
Benadryl£3.894.7★
Benadryl Allergy Relief Capsules (1 x 24) Antihistamine Capsules with Acrivastine Hayfever Tablets for Relief Suitable for Pet Dust and Skin Allergies
Benadryl£5.504.6★
240 x 10mg Cetirizine Dihydrochloride (8 Months Supply) One a Day hay Fever and Allergy Relief Tablets (8x30 Tablets)
Crescent Pharma Limited£4.854.8★
What buyers say about diphenhydramine
What buyers praise and complain about, mined from review topics.What buyers love
“Good value”
“Allergy relief”
“The best hay fever relief”
“Very effective”
“Does what it says on the package”
“Good quality”
“Such an easy way to purchase”
“Especially good for nighttime relief”
“Sweet”
“Grain free antihistomine”
What buyers complain about
“Obviously they're the most expensive tablets”
“doesn't contain many doses”
“It doesn't state age limit on box”
“I find these make me drowsy”
“Didnt work for me”
“Ineffective”
“Hay-fever tablets”
“The only allergy tablets. including prescription”
“itching skin can be a real problem”
“The only issue is the bottle is small”
Common questions
- Is diphenhydramine profitable to sell on Amazon United Kingdom?
- The niche generates £200K/yr across 5 tracked products. 90-day search growth is +16.8%. Flapen's verdict: Skip it (36/100).
- How competitive is the diphenhydramine niche?
- 2 brands and 82 sellers compete. The top 5 products take 100% of clicks and top 5 brands hold 100% of demand.
- What do buyers complain about in diphenhydramine?
- Top complaints mined from reviews: Value For Money, Dosage, Age Suitability. The return rate is 0.0%.
- What does it cost to enter the diphenhydramine niche?
- Listings span £3.89–£6.76; the average listing price is £5.09 (sweet spot $15–$100). The average incumbent carries 4,080 reviews — the moat a new listing must climb.