Relentless Improvement: do you self test the purity of overseas ingredients before production of D-Serine?

When the active arrives we sample it and send it out to a third-party analytical testing laboratory based in the USA. The material is quarantined until test results are received back. **As is required for GMP compliance.**

Is this made in the usa? is it based on porcine aka pig, or shell fish?

The active is not available from USA suppliers. As you are well aware, our high-tech manufacturing was gutted and shipped offshore decades ago. Downstream of the active, all remaining manufacturing and testing is USA. The is no porcine, or shellfish.

Relentless Improvement: do you third party test the purity of overseas ingredients before production of third D-Serine?

As required under GMP, yes. OF COURSE. We have conducted full third-party testing since we began business 17 years ago, before it was required by law. I'll also point out, 99% of actives used by ALL supplement companies come from "overseas" as USA manufacturing was gutted decades ago.

For anyone who's tried both L-Serine & D-Serine, did D-Serine really achieve better results?

Because D-Serine has a poor absorption rate orally one must take a lot. I gave to my wife for three months when recovering. I don't know how well it worked but I would do again.

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Relentless Improvement D-セリン

Product ID: 735149005

Details

Brand
Relentless
Dosage Form
カプセル
Flavor
アンフレーバー
Item Form
カプセル
Item Weight
0.11 Kilograms
Item dimensions L x W x H
6.4 x 5.1 x cm

🌱90 vegecaps, clean & stearate-free

💊700mg pure D-Serine per capsule

🧠Supports cognitive & mood health

€ 159.63

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Sold byAmazon FranceDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

🧠 Elevate your mind, own your day with D-Serine!

PURE COGNITIVE BOOST - Each capsule delivers a potent 700mg of D-Serine, fueling your brain’s natural performance.
CLEAN GREEN FORMULA - 90 vegetable-based capsules free from magnesium stearate for a pure, allergen-conscious supplement.
TAILORED DOSAGE FLEXIBILITY - Recommended 3-4 capsules daily, with benefits increasing up to 6-8 capsules based on your needs.
MOOD MENTAL CLARITY SUPPORT - Scientifically designed to enhance emotional balance and cognitive function for the busy professional.
TRUSTED QUALITY BY RELENTLESS IMPROVEMENT - Backed by a 4.2-star rating and crafted with premium ingredients for your wellness journey.

D-Serine by Relentless Improvement is a high-potency, clean-label amino acid supplement designed to support healthy cognition and mood. Each capsule contains 700mg of pure D-Serine in a vegetable capsule free from magnesium stearate, offering flexible dosing from 3 to 8 capsules daily. Perfect for professionals seeking mental clarity and emotional balance, this supplement combines science-backed ingredients with trusted quality.

Specifications

ASIN	B09TWCN545
ASIN	B09TWCN545
Brand Name	Relentless Improvement
Customer Reviews	4.2 4.2 out of 5 stars (23)
Dosage Form	カプセル
Flavor	アンフレーバー
Item Dimensions	6.4 x 5.1 x 5.1 cm
Item Form	カプセル
Item Weight	0.11 Kilograms
Item model number	DSERINE_FBM
Manufacturer	Relentless Improvement
Manufacturer	Relentless Improvement
Manufacturer Part Number	DSERINE_FBM
Model Number	DSERINE_FBM
Number of Items	1
Product Dimensions	6.35 x 5.08 x 5.08 cm; 111 g
Specific Uses For Product	感情的なサポート
UPC	854463005412

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€ 159.63

Duties & taxes included

In stock

Sold byAmazon FranceDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to France.

Secure transaction

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Meera L.

Smooth transaction and product arrived in perfect condition.

3 weeks ago

Sneha T.

Received my product in pristine condition. Great service overall.

1 month ago

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