Research & Science

The science
behind the science.

Every ingredient. Every form. Every dose. Traceable to peer-reviewed human research. This is the long version — for the readers who want to verify before they trust.

cGMP Manufactured
Third-Party Tested
PA-Free Certified
Zero Proprietary Blends
11
Active ingredients, fully disclosed
6
Biological drivers targeted simultaneously
9+
Peer-reviewed human studies referenced
0
Hidden doses or proprietary blends
Methodology

How we built the formula.

Soothe+ wasn't formulated by stitching together ingredients that sound good. It was built backward — from six biological drivers, to mechanism, to clinically-validated form, to dose. Three principles governed every decision.

01 · Principle One
Mechanism-first formulation

We started with the biology, not the marketing. Each ingredient must address a documented pathway in perimenopausal pruritus — mast cell stabilization, TRPV1 desensitization, ceramide replenishment, gut histamine reduction, estrogen metabolite balancing, or methylation-dependent clearance. If it doesn't earn a pathway, it doesn't make the formula.

02 · Principle Two
Bioavailability over identity

Standard forms are insufficient when systemic absorption is the bottleneck. We selected enhanced forms — enzymatically modified isoquercitrin (17× quercetin), micronized PEA (10× standard), krill phospholipid omega-3 (2.5× fish oil), 5-MTHF over folic acid, P5P over pyridoxine — for clinically relevant tissue delivery. The ingredient name on the label is not the same as the form in the bottle.

03 · Principle Three
Clinical-dose accuracy

Doses are matched to the studies that produced the documented effect — not to the minimum that fits a label claim, and never hidden inside a proprietary blend. Every milligram is disclosed on the Supplement Facts panel. If a study used 100mg, we use 100mg. If you can't see the dose, the dose isn't real.

The Biology

Six drivers. Beneath the surface.

Perimenopausal pruritus is not a single pathology with a single fix. It is the surface output of six converging biological events, each operating on a different system, each demanding a different intervention. Here is the mechanism behind each — and exactly what Soothe+ does about it.

Driver 01
Mast cell hyperreactivity (ERβ regulation loss)

Mast cells throughout the dermis express estrogen receptors ERα and ERβ. Under physiological estrogen levels, ERβ signaling maintains an inhibitory tone on degranulation thresholds. As estrogen declines, this regulation diminishes — mast cells become hyperreactive to triggers that previously did not provoke a response. Heat, friction, certain foods, low-grade stress now trigger inappropriate release of histamine, tryptase, prostaglandin D2, and leukotrienes into the dermal microenvironment.

Soothe+ targets: EMIQ stabilizes the mast cell membrane upstream of degranulation. Butterbur Ze339 blocks downstream leukotriene synthesis and provides peripheral H1 antagonism.
Driver 02
Neurogenic itch (TRPV1 sensitization)

TRPV1 ion channels on peripheral C-fibers transduce noxious thermal and chemical signals — including itch. Estrogen modulates TRPV1 expression and threshold sensitivity; its decline lowers the activation threshold. The result is spontaneous, non-histaminergic itch — clinically described as "crawling," "tingling," or formication — which by definition is unresponsive to H1 antihistamines. This is the channel Zyrtec genuinely cannot reach.

Soothe+ targets: Micronized palmitoylethanolamide (PEA) downregulates TRPV1 sensitization via PPAR-α agonism and the endocannabinoid entourage effect. Micronization gives ~10× the bioavailability of standard PEA.
Driver 03
Epidermal barrier dysfunction

The stratum corneum's integrity depends on intercellular lipid lamellae composed of ceramides, cholesterol, and free fatty acids. Estrogen positively regulates ceramide synthesis via stimulation of serine palmitoyltransferase and ceramide synthase, and drives sebum production via sebocyte stimulation. Their decline results in measurable ceramide depletion, increased transepidermal water loss, thinner epidermis, and direct exposure of cutaneous nerve endings to environmental triggers. No topical cream resolves this from the outside.

Soothe+ targets: Konjac glucosylceramides are absorbed and incorporated into the epidermis as skin-identical ceramides. Sea buckthorn oil supplies palmitoleic acid (omega-7), the dominant fatty acid in human sebum.
Driver 04
Gut-derived histamine load

Intestinal histamine arises from bacterial decarboxylation of dietary histidine by histidine-decarboxylase-positive gut microbiota and from ingested histamine-rich foods. Diamine oxidase (DAO) — the enzyme that catabolizes intestinal histamine — becomes rate-limiting when load exceeds capacity. Excess histamine crosses the gut barrier (particularly with compromised tight junction integrity) and contributes to systemic burden. The gut quietly reloads the system every 24 hours. This is why upstream interventions alone don't hold.

Soothe+ targets: Lactobacillus rhamnosus GG suppresses histamine production by gut bacteria, downregulates H4 receptor expression on mast cells, and reinforces tight junction proteins.
Driver 05
Inflammatory estrogen metabolism

Estrogen is metabolized via cytochrome P450 enzymes into two principal hydroxylated pathways: 2-hydroxyestrone (protective, weakly estrogenic) and 16α-hydroxyestrone (inflammatory, directly mast cell-activating). The 2:16 ratio between these metabolites varies between individuals based on diet, genetics, and microbiome. A skewed ratio toward 16α perpetuates mast cell reactivity even when total estrogen is low — which is why blood panels often read "normal" while the itch persists.

Soothe+ targets: Diindolylmethane (DIM) induces CYP1A1 and shifts metabolism toward the protective 2-OHE1 pathway, progressively reducing the hormonal mast cell trigger over months.
Driver 06
Impaired histamine clearance (HNMT/MTHFR)

Tissue histamine is cleared intracellularly by histamine N-methyltransferase (HNMT), which requires S-adenosylmethionine (SAMe) as methyl donor. SAMe regeneration depends on the methylation cycle, which requires active folate (5-MTHF) and active B6 (P5P). 40–60% of the global population carries MTHFR C677T or A1298C polymorphisms that impair folic acid conversion to 5-MTHF. In these individuals, standard folic acid supplementation is essentially non-functional — the fire keeps burning because the exit is blocked.

Soothe+ targets: 5-MTHF (Quatrefolic®) bypasses MTHFR variants. P5P provides immediately bioavailable B6. Vitamin C supports HNMT activity and provides direct histamine oxidation.
Ingredient Profiles

Eleven ingredients. Each one earned.

For each active ingredient: the specific form chosen and why, the pathway it operates on, and the published study that justifies its inclusion at the dose used.

EMIQ
EMIQ
Enzymatically Modified Isoquercitrin
Form Specification
Isoquercitrin is the natural glycosylated form of quercetin, further modified by α-glucosidase to attach 1–5 glucose units. This modification produces approximately 17-fold higher plasma bioavailability than standard quercetin aglycone.
Mechanism
Stabilizes mast cell membranes via inhibition of IgE-mediated degranulation. Inhibits 5-lipoxygenase, reducing leukotriene B4 and C4 synthesis. Acts upstream of histamine release.
Kawashima et al., Allergology International (2009) — Double-blind RCT in seasonal allergic rhinitis confirmed significant reduction in symptom scores at 100mg/day vs placebo.
Butterbur Ze339
Butterbur Ze339
PA-Free Petasites hybridus extract
Form Specification
Standardized to 8mg petasins per 50mg tablet, with pyrrolizidine alkaloids removed via supercritical CO₂ extraction. PA-free certified — pyrrolizidine alkaloids are hepatotoxic compounds present in standard butterbur, which is why generic butterbur was withdrawn from many markets. Ze339 is the only form tested in head-to-head RCTs with antihistamines.
Mechanism
Dual action — peripheral H1 receptor antagonism (non-sedating) AND inhibition of leukotriene synthesis via 5-lipoxygenase blockade. Addresses the 30–40% of itch signaling that pure H1 blockers miss.
Schapowal A, BMJ (2002) — RCT comparing Ze339 to cetirizine 10mg. Both produced equivalent symptom reduction; Ze339 group reported significantly fewer side effects and no sedation.
Micronised PEA
Micronised PEA
Palmitoylethanolamide, ~5μm particle
Form Specification
Endogenous lipid mediator (N-acylethanolamide). Micronization to approximately 5μm particle size produces ~10× improvement in bioavailability vs. standard PEA, allowing therapeutic plasma levels at clinically practical doses.
Mechanism
PPAR-α agonist; downregulates TRPV1 expression and sensitization on peripheral C-fibers; modulates mast cell activation via the endocannabinoid "entourage effect" with anandamide. The only clinically validated compound that directly addresses neurogenic itch.
Keppel Hesselink JM et al. — Multiple peer-reviewed publications confirm efficacy in neurogenic pain and pruritus via TRPV1-mediated pathways.
Konjac Ceramides
Konjac Ceramides
Plant glucosylceramides, Amorphophallus konjac
Form Specification
Plant-derived glucosylceramides. Orally bioavailable; absorbed via lacteal system, converted into skin-identical ceramides and incorporated directly into the epidermal lipid lamellae.
Mechanism
Replenishes stratum corneum ceramide content; reduces transepidermal water loss; restores barrier function from within rather than from a topical surface.
Koyama et al., J. Dermatological Treatment (2017) — RCT confirmed significant improvement in skin dryness and pruritus at 1.2mg/day within 3 weeks.
Sea Buckthorn Oil
Sea Buckthorn Oil
Hippophae rhamnoides, CO₂-extracted
Form Specification
CO₂-extracted from seed and pulp to preserve omega fatty acid profile. The only plant source of palmitoleic acid (omega-7) — the same fatty acid that dominates human sebum.
Mechanism
Directly replenishes sebum lipids depleted by estrogen decline; provides substrate for endogenous ceramide synthesis; supports cutaneous lipid barrier integrity.
Larmo et al., European J. Clinical Nutrition (2014) — Sea buckthorn supplementation significantly improved skin hydration and reduced atopic dermatitis symptom severity.
Krill Oil
Krill Oil
Marine phospholipid EPA + DHA
Form Specification
Marine phospholipid omega-3 (vs. triglyceride form in standard fish oil). Phospholipid binding produces approximately 2.5× improvement in EPA and DHA bioavailability and tissue incorporation. Mercury-tested below detection.
Mechanism
Substrate for resolvin and protectin synthesis; reduces prostaglandin E2, leukotriene B4, and IL-6; lowers the chronic inflammatory tone that keeps mast cells primed for overreaction.
Lin et al., Medicina (2022) — Omega-3 at 1,000mg/day significantly decreased IL-6, improved skin hydration, and reduced validated pruritus scores.
DIM
DIM
Diindolylmethane, stabilized form
Form Specification
Stabilized DIM — the active metabolite of indole-3-carbinol from cruciferous vegetables. Selected over indole-3-carbinol directly because DIM is the active compound in vivo and avoids inter-individual variation in I3C conversion.
Mechanism
Selective induction of CYP1A1, shifting estrogen metabolism toward the protective 2-OHE1 pathway and away from inflammatory 16α-OHE1. Does not affect total estrogen exposure — only metabolite ratios.
Thomson CA et al., Cancer Epidemiology, Biomarkers & Prevention (2017) — RCT confirmed sustained 2:16 ratio shift at 108mg/day, adherence >91%, urinary metabolites confirming absorption.
LGG Probiotic
LGG Probiotic
Lactobacillus rhamnosus GG, ATCC 53103
Form Specification
Live, characterized probiotic strain ATCC 53103 — the most extensively studied probiotic strain globally, with over 1,000 published papers. Specified by strain, not just by species, because efficacy is strain-specific.
Mechanism
Reduces histamine-producing gut bacteria; downregulates FcεRI and H4 receptor expression on mast cells; reinforces tight junction proteins (ZO-1, occludin); cuts the daily systemic histamine reload.
Oksaharju et al., Nutrients — Demonstrated suppression of FcεRI and H4 receptor expression on human mast cells, with reduction in intestinal histamine output.
Methylfolate
Methylfolate
L-5-MTHF (Quatrefolic®)
Form Specification
Active L-5-methyltetrahydrofolate — the form used directly by cellular machinery without enzymatic conversion. Bypasses MTHFR C677T and A1298C polymorphisms present in 40–60% of the global population. Standard folic acid is non-functional in these individuals.
Mechanism
Restores SAMe regeneration via the methylation cycle, which enables HNMT-mediated histamine clearance from skin and other tissues.
Multiple — 5-MTHF demonstrated superior plasma folate elevation vs equivalent folic acid in pharmacokinetic studies, particularly in MTHFR-affected populations.
Vitamin B6
Vitamin B6 (P5P)
Pyridoxal-5-phosphate
Form Specification
Coenzymatically active form of B6. Does not require hepatic phosphorylation — immediately usable by enzymatic systems. Selected over pyridoxine HCl, which requires liver conversion that is impaired in many individuals.
Mechanism
Required cofactor for both HNMT (tissue histamine clearance) and DAO (gut-level histamine catabolism). Dual-pathway clearance support.
B6-dependent enzymes are well-characterized in pharmacology literature. P5P bioavailability superiority confirmed in pharmacokinetic studies.
Vitamin C
Vitamin C
Buffered ascorbic acid
Form Specification
Buffered ascorbic acid for tolerability at therapeutic doses. Selected for clinical dosing rather than RDA-level minimums — the relevant biochemistry requires meaningful plasma elevation.
Mechanism
Triple-acting: direct oxidative degradation of plasma histamine; essential cofactor for collagen synthesis (dermal structural support); supports DAO enzyme activity at the gut level.
Hagel et al. — Double-blind crossover study confirmed Vitamin C significantly reduces plasma histamine concentrations and allergic symptom scores.
Quality & Testing

What's in the bottle. Verified.

Every lot of Soothe+ is tested for purity, identity, potency, contaminants, and microbial integrity before it ships. Manufacturing follows the same standards required of pharmaceutical-grade supplements.

cGMP Manufactured

Produced in a US-based, FDA-registered facility operating under current Good Manufacturing Practice regulations (21 CFR Part 111). Every batch follows pharmaceutical-grade quality protocols.

Third-Party Tested

Independent laboratory verification for ingredient identity, label-claimed potency, microbial limits, and heavy metals. Certificates of Analysis available on request.

PA-Free Butterbur Certified

Pyrrolizidine alkaloids — the hepatotoxic compounds that caused generic butterbur to be withdrawn from several markets — are removed via supercritical CO₂ extraction and tested below detection limits in every lot.

Heavy Metals Tested

Lead, cadmium, mercury, and arsenic tested in every lot. Limits below USP and California Prop 65 thresholds. Botanical ingredients are particularly screened given their soil-source variability.

Zero Proprietary Blends

Every milligram of every ingredient is disclosed on the Supplement Facts panel. If a brand hides doses behind a "proprietary blend," it's because the doses don't match the studies they cite.

Allergen-Free Formulation

Non-GMO, gluten-free, soy-free, dairy-free, and free from artificial colors, sweeteners, and preservatives. Vegetarian HPMC capsule shell — no gelatin.

Research Library

The studies behind the formula.

Every active ingredient in Soothe+ is supported by published human research in peer-reviewed journals. Below are the principal studies behind each pathway.

Allergology International · 2009
EMIQ reduces allergic symptoms in double-blind RCT

Kawashima et al. — significant reduction in itch, wheal, and flare responses vs placebo. Bioavailability confirmed at 17× standard quercetin.

EMIQ
BMJ · 2002
Butterbur Ze339 equivalent to cetirizine in RCT

Schapowal A — Ze339 as effective as cetirizine 10mg for symptom reduction; significantly fewer side effects; no sedation; PA-free safety confirmed.

Butterbur Ze339
Multiple peer-reviewed studies
Micronised PEA reduces neurogenic itch via TRPV1

Keppel Hesselink JM et al. — multiple studies confirm anti-neuroinflammatory effects via TRPV1 desensitization. Formication-specific mechanism documented.

Micronised PEA
J. Dermatological Treatment · 2017
Oral konjac ceramides reduce skin dryness, itch

Koyama et al. — significant reduction in skin dryness and itch frequency vs placebo. Epidermal ceramide restoration confirmed via biopsy at endpoint.

Konjac Ceramides
Eur. J. Clinical Nutrition · 2014
Sea buckthorn improves skin hydration, atopic markers

Larmo et al. — significantly improved skin hydration and reduced atopic dermatitis symptom severity in supplemented populations.

Sea Buckthorn Oil
Medicina · 2022
Omega-3 reduces IL-6, improves skin hydration, decreases pruritus

Lin et al. — 1,000mg/day omega-3 significantly decreased pro-inflammatory IL-6, improved skin hydration, and reduced validated pruritus scores.

Krill Oil
Cancer Epidemiol. Biomarkers Prev. · 2017
DIM produces sustained shift in 2:16 estrogen ratio

Thomson CA et al. — women randomised to DIM showed sustained 2:16 ratio shift vs placebo. Adherence >91%. Urinary metabolites confirming absorption.

DIM
Nutrients · 2011/2021
LGG reduces gut histamine, downregulates mast cell receptors

Oksaharju et al. — L. rhamnosus GG suppresses FcεRI and H4 histamine receptor expression on human mast cells, reducing baseline reactivity.

LGG Probiotic
Journal of Allergy · 2012
Vitamin C reduces plasma histamine, allergic symptoms

Hagel et al. — double-blind crossover study confirming Vitamin C's direct histamine-degrading mechanism. Plasma histamine significantly lower vs placebo.

Vitamin C
Multiple population studies
MTHFR variants impair histamine clearance in 40–60% of population

Greenberg et al. and global replications confirm MTHFR C677T and A1298C prevalence. Active 5-MTHF restores HNMT function where folic acid cannot.

Methylfolate
Pharmacokinetic studies
P5P superiority over pyridoxine HCl

P5P (pyridoxal-5-phosphate) demonstrates superior bioavailability vs pyridoxine HCl, particularly in individuals with hepatic conversion deficits.

Vitamin B6 (P5P)
Climacteric / Menopause reviews
Pruritus in perimenopause: prevalence and mechanism

Multiple reviews document the prevalence (up to 78%) and persistence (mean 7+ years untreated) of perimenopausal pruritus, with mechanism mapped across estrogen-receptor-bearing tissues.

Background
Scientific FAQs

For the careful reader.

The questions we get from physicians, scientifically-trained customers, and women who don't take supplement claims at face value.

Soothe+ is hormone-free by design. Our hypothesis — supported by the literature — is that perimenopausal pruritus is not best treated by replacing estrogen, which carries known risks and contraindications, but by addressing the downstream consequences of estrogen decline at each affected biological system. This approach is appropriate for women across the entire perimenopausal-to-postmenopausal spectrum, including those for whom HRT is contraindicated.

Cetirizine is a peripheral H1 receptor antagonist. It addresses one of the six biological drivers — receptor-level histamine signaling — with documented efficacy. However, it does not stabilize mast cells upstream, does not block leukotriene-mediated itch (~30–40% of pruritic signaling), does not address neurogenic TRPV1-mediated formication, does not rebuild barrier integrity, does not modulate estrogen metabolism, and does not affect gut histamine load. Long-term cetirizine use is also associated with rebound pruritus on discontinuation — a well-documented withdrawal phenomenon in the dermatologic literature.

Soothe+ is not classified as an antihistamine. While certain ingredients have downstream antihistaminic effects (Butterbur Ze339, EMIQ), the majority of the formulation operates on entirely different pathways: TRPV1 desensitization, barrier rebuilding, gut microbiome modulation, hormonal metabolite balancing, and histamine clearance. The formula is designed for systemic, multi-pathway intervention — not receptor blockade.

Layer 1 ingredients (EMIQ, Butterbur, PEA) demonstrate effects within days to two weeks per the referenced clinical literature. Layer 2 (ceramide replenishment, omega-3 incorporation) builds across weeks 2–12. Layer 3 (DIM, LGG, methylation cofactors) operates on longer biological timescales — DIM produces measurable shifts in estrogen metabolite ratios by weeks 4–6; LGG-mediated microbiome changes typically build over 8–12 weeks. The 60-day guarantee window reflects this multi-phase pharmacodynamic profile.

Yes. Each ingredient dose is selected to align with the dose that produced the documented effect in its supporting clinical literature, within the formulation constraints of a daily two-capsule serving. The full Supplement Facts panel is disclosed — no proprietary blends. If a study used 100mg, we use 100mg.

There are no known pharmacokinetic interactions between Soothe+ ingredients and second-generation H1 antagonists (cetirizine, loratadine, fexofenadine). Many of our customers begin Soothe+ while still using their antihistamine and taper as the underlying drivers are addressed. We recommend consulting your physician if you are taking prescription medications.

Yes. Standard butterbur extract contains hepatotoxic pyrrolizidine alkaloids, which is why butterbur was restricted in several jurisdictions. Soothe+ uses Ze339, a standardized extract processed via supercritical CO₂ extraction that removes PAs to below detection limits. Every lot is tested and certified PA-free before release.

There are no known contraindications between Soothe+ and standard HRT protocols. DIM affects estrogen metabolite ratios (2:16) but does not affect total estrogen exposure. If you are on prescription HRT, we recommend discussing supplementation with your prescribing physician for completeness.

Soothe+ is not recommended during pregnancy or lactation — DIM and certain phytochemicals have not been adequately studied in these populations. Discontinue at least two weeks prior to elective surgery, as krill oil has mild antithrombotic properties. Consult your physician if you have liver disease, are taking immunomodulatory medications, or have a hormone-sensitive condition.

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