Our verdict on Synadentix
What we liked
- The full ingredient list is printed on the label image the vendor publishes
- Its actives are ones used in oral-care products, such as hydroxyapatite, lactoferrin and salivary enzymes
- No stimulants, and a one-time charge with no autoship
- A 90-day refund window counted from delivery, with free US shipping on the 3 and 6 bottle orders
Watch out for
- All 10 actives sit inside one 400 mg proprietary blend, with no individual dose
- The vendor's research is mostly toothpaste, topical or lab work, not a swallowed tablet
- The vendor gives three different sets of directions
- Big claims about teeth, the brain and detox, with no study of the product
- A refund means mailing every bottle back at your own cost
- No single-bottle option and no company name or owner disclosed
JillLebofsky may earn a commission if you buy through links on this page, at no extra cost to you. That does not change what we report.
Synadentix is a soft chewable tablet sold online for teeth and gums, and the honest answer on whether it helps is that nobody has tested it. Its label lists 10 actives inside a single 400 mg proprietary blend, which works out to about 40 mg each if split evenly, and the real split is not disclosed[2].
Several of those ingredients have real research behind them, but mostly as toothpaste, rinse or lab work. Below we set out the label, the evidence, the price and the refund terms as we checked them on October 28, 2026. Our method is on the how we check products page.
What is Synadentix and what does the vendor claim?
The sales page goes further. The vendor says the real problem behind teeth and gum trouble "isn't poor hygiene, it's P. gingivalis," and that the formula "deeply cleanses your mouth of bad bacteria and toxins" while it "protects your brain"[1]. It also describes "NASA-grade Microcrystalline Hydroxyapatite Complex, clinical lactoferrin, and marine enzymes," wording that does not appear on the label.
The contact FAQ adds claims of "improved heart, brain, and immune health"[3]. None of these claims comes with a study of the tablet itself. The label names no company or owner, only "Distributed by Synadentix" at 285 Northeast Ave, Tallmadge, OH 44278, an address the refunds page labels as a fulfilment warehouse[4].
Synadentix facts at a glance
Synadentix is a 30-count chewable tablet whose 10 actives share one undisclosed 400 mg blend, sold only online through BuyGoods for $158 to $294 per order, with a 90-day refund window counted from delivery. Every row below comes from the vendor's own pages, checked October 28, 2026.
| Item | What we found |
|---|---|
| What it is | Oral-health dietary supplement[1] |
| Form and serving | Soft chewable tablet, 1 tablet per serving, 30 per bottle[2] |
| Ingredients disclosed? | Names yes, amounts no: one 400 mg proprietary blend[2] |
| Price range | $158 (2 bottles) to $294 (6 bottles), checked October 28, 2026[6] |
| Refund window | 90 days from delivery, buyer pays return postage[4] |
| Seller | Vendor site, checkout by BuyGoods[6] |
| Not sold by the vendor on | Amazon or Walmart (the vendor says it sells only through its own page)[3] |
Who might consider Synadentix, and who should not?
Synadentix may appeal to adults with healthy teeth and gums who already brush and floss and want an extra product with oral-care ingredients. It is no substitute for a dental exam. Bleeding gums, loose teeth, tooth pain or swelling need a dentist, not a tablet.
Skip it or ask a clinician first if any of these apply:
- You have a milk or egg allergy. Lactoferrin and lactoperoxidase are usually milk-derived and lysozyme usually egg-derived, and the label does not state the source[19].
- You are pregnant or nursing, under 18, or have a known medical condition. The label itself says to ask a physician[2], even though the contact FAQ calls the tablet "designed for all ages and medical conditions"[3].
- You take blood thinners or antiplatelet drugs, given a study linking xylitol to higher platelet reactivity[21].
- You have a dog at home. Xylitol, listed among the other ingredients, is toxic to dogs.
People who want to know exact doses before they buy will not find them on this label.
How does Synadentix claim to work?
The vendor claims Synadentix works by "reactivating your body's natural ability" to restore teeth overnight through more saliva flow, and by sending ingredients "directly into your bloodstream" to detox "at the cellular level"[1]. These are vendor claims, and no study of the product supports them.
What is known is narrower. Hydroxyapatite is a mineral used in toothpaste, where it rests on the tooth surface during brushing[10]. Lactoferrin, lysozyme and lactoperoxidase are proteins and enzymes found in saliva, and glucose oxidase feeds the lactoperoxidase system by making hydrogen peroxide. Dextranase and beta-glucanase break down sugars that plaque bacteria use to stick to teeth, which has been shown mainly in lab models[14].
A tablet held for 30 seconds and swallowed gives these ingredients far less contact time than toothpaste. The vendor's own reference list cites mostly toothpaste, topical and lab studies[2]. We look at that gap in detail in does Synadentix work.
What ingredients are in Synadentix?
Synadentix contains 10 actives in a 400 mg proprietary blend: guava fruit powder, microcrystalline hydroxyapatite, lactoferrin, lysozyme, lactoperoxidase, glucose oxidase, dextranase, amylase, amyloglucosidase and beta-glucanase. No individual dose is listed[2]. The other ingredients are xylitol, microcrystalline cellulose, magnesium stearate and natural flavoring.
The grades below reflect human evidence for oral health in the form Synadentix uses: a swallowed tablet. An ingredient with good toothpaste data can still score low here.
| Ingredient | Dose disclosed? | Best human evidence and form | Grade |
|---|---|---|---|
| Microcrystalline hydroxyapatite | No | Toothpaste: about 17% caries protection in a meta-analysis[10]; 18-month trial non-inferior to fluoride paste[11]. No tablet trial | Moderate as toothpaste, Weak as a tablet |
| Lactoferrin | No | Tablets with lactoperoxidase: 60 mg a day lowered gum inflammation scores in 150 adults over 12 weeks; 20 mg did not[8] | Limited |
| Lactoperoxidase | No | Only tested in tablets together with lactoferrin[8][9] | Limited |
| Lysozyme | No | Toothpaste: minor mouth ulcers closed faster in 71 adults[12]. No swallowed data | Weak |
| Glucose oxidase | No | Enzyme toothpaste showed no difference against comparators[13] | Weak |
| Amyloglucosidase | No | Same null enzyme toothpaste trials[13] | Weak |
| Dextranase | No | 1970s rinse and gum work: "limited clinical success"[14] | Weak |
| Beta-glucanase | No | Multi-enzyme lozenge: slightly less plaque at one dose, no gum benefit[18] | Weak |
| Guava fruit powder | No | 200 g of fresh fruit a day cut plaque and gum inflammation[15]; leaf rinse helped gums[16] | Weak |
| Amylase | No | No oral-health trial; lab work shows it can help plaque bacteria reach sugar[17] | Weak |
| Xylitol (other ingredient) | No | Low-quality evidence for caries in toothpaste and gum[22] | Moderate in toothpaste and gum |
Two numbers stand out. The guava trial used 200 g of fruit a day, about 5,000 times a 40 mg share of powder[15]. The lactoferrin trial needed 60 mg a day, and the label gives no way to tell whether one or two tablets reach that[8].
Does Synadentix work for teeth and gums?
No study shows Synadentix works for teeth and gums, because no trial of the finished tablet exists. A few of its ingredients have human data, mostly in toothpaste, and only one pair has a positive trial in tablet form, at a dose the label cannot confirm.
Step 1: is it plausible?
Partly. Saliva naturally contains lactoferrin, lysozyme and lactoperoxidase, and hydroxyapatite is the mineral of tooth enamel. A plausible mechanism is still only a starting point.
Step 2: do the ingredients work in trials?
Hydroxyapatite toothpaste performed about as well as fluoride toothpaste over 18 months in 189 adults[11]. That was brushed on twice a day for months. Lactoferrin 60 mg plus lactoperoxidase 7.8 mg a day in tablets lowered gingival index scores against placebo over 12 weeks, while the lower dose did not[8]. Sucked tablets of the same pair reduced tongue and plaque bacteria in older adults, an outcome that is not the same as healthier gums[9]. Glucose oxidase toothpaste showed no difference against comparators[13].
Step 3: has the product been tested?
No. We found no published trial of Synadentix. The "13,451 reviews" figure on the sales page is not a study, and the page script uses placeholder names "Actor 1" and "Actor 2" for its testimonial personas[1]. Read the full breakdown in our check of whether Synadentix works, and see what Synadentix oral support claims mean.
Synadentix side effects: who should ask a doctor first?
We found no published side-effect data for Synadentix itself, and the FDA adverse event database had no reports for it on October 28, 2026[24]. The main known risks come from individual ingredients, chiefly allergy.
- Egg allergy: lysozyme is usually made from egg white, and 5 of 21 egg-sensitized children reacted to a lysozyme-containing cheese[19].
- Milk allergy: lactoferrin and lactoperoxidase are usually from cow milk; the label does not say.
- Almond allergy: glucose oxidase shares sequence likeness with an almond allergen, a theoretical concern[20].
- Blood thinners and antiplatelet drugs: a xylitol drink raised platelet reactivity in healthy people[21]. Ask your doctor or pharmacist.
- Pregnancy, nursing, under 18, medical conditions: the label says ask a physician first[2].
See a doctor or dentist right away if you have:
- Swelling of the lips, tongue, face or throat, hives, or trouble breathing after a tablet
- Facial swelling or fever with tooth pain
- Gums that bleed heavily or do not stop bleeding
- A loose adult tooth or pain that keeps you awake
What do Synadentix complaints and buyer reports show?
We could not verify independent buyer reports for Synadentix as of October 28, 2026. The Better Business Bureau search did not return a parsable profile, so BBB is NOT checked[25]. Trustpilot blocked access and had no archived copy, so Trustpilot is NOT checked.
Federal records gave a narrower picture. openFDA returned no recall records for Synadentix[23] and no adverse event reports in CAERS[24]. The FDA Health Fraud Product Database did not load, so it is NOT checked.
The vendor's own numbers need care. The sales page claims "13,451 reviews" and "96% Of Customers Order 6 Bottles," with no way to verify either[1]. The vendor domain's earliest Wayback capture is July 14, 2025[26], so it is a young product. Our Synadentix complaints page tracks what buyers report as sources open up.
How much does Synadentix cost?
Synadentix costs $158 for 2 bottles, $207 for 3 or $294 for 6, per the vendor page checked October 28, 2026[6]. There is no single-bottle option. The vendor shows a "was" price of $179 a bottle, which we do not count as a real regular price.
2 bottles
6 bottles
3 bottles| Package | Per bottle | Total | US shipping | Supply at 1 a day |
|---|---|---|---|---|
| 2 bottles | $79 | $158 | $9.99 on the price grid | 60 days |
| 3 bottles ("2 + 1") | $69 | $207 | Free | 90 days |
| 6 bottles ("3 + 3") | $49 | $294 | Free, plus 3 bonus ebooks | 180 days |
The shipping policy page says US shipping is free on all orders, but the price grid adds $9.99 to the 2-bottle order[5][6]. BuyGoods checkout totals were NOT captured. It is a one-time charge with no autoship[3]. After checkout, offers of 3, 6 or 12 more bottles at $29 each appear; decline any you did not plan for. At the label maximum of 2 tablets a day, one bottle lasts 15 days. More detail is on our Synadentix price and coupon page.
What is the Synadentix refund policy?
Synadentix offers a 90-day money-back guarantee counted from the delivery date, not the order date[4]. You must ship every bottle back at your own cost.
- Email support with "Refund Request" in the subject line.
- Mail ALL bottles, empty or not, plus the packing slip and a note with your name, email and order ID, to 285 Northeast Ave, Tallmadge, OH 44278.
- Wait 5 to 10 days for the refund to show on your card[4].
Return postage is not refunded. The vendor pages conflict: the sales page promises to "refund every single cent," and the contact FAQ says "return what you haven't used," while the refunds page requires all bottles[1][3]. The refund badge image is even named "60days." BuyGoods also handles order support.
Where can you buy Synadentix?
Synadentix is sold through the vendor's site with checkout on BuyGoods. The vendor says the product "can be found only on this page"[3], yet at least one third-party site also sells it, so that claim is not accurate.
Listings on Amazon, Walmart or eBay are not covered by the vendor's 90-day guarantee, and a resold bottle may be old, stored badly or not genuine. If you buy, the vendor checkout is the only route with the stated refund terms. Our Synadentix on Amazon and Walmart page covers what we found on each marketplace, and readers outside the US can see Synadentix in the UK, Canada and Australia.
Is Synadentix legit?
Synadentix is a real product sold through a known retailer, BuyGoods, with published refund terms and a label. Several facts still call for caution. No company name or owner appears anywhere; the terms page names no operating company[7], and the only address is a fulfilment warehouse.
The contact FAQ calls the factory "FDA accredited," but FDA registers facilities and does not accredit them; the same FAQ correctly says FDA does not review supplements[3]. The testimonial personas use placeholder names in the page code[1]. We set out each seller fact in is Synadentix legit.
Synadentix vs other approaches to teeth and gums
For teeth and gums, the options with the most trial support are toothpastes used every day, plus regular dental care. A swallowed tablet has the least direct evidence.
| Approach | Strength | Limitation |
|---|---|---|
| Hydroxyapatite or fluoride toothpaste, twice a day | Trials over 18 months show caries protection[11] | Works only if used daily |
| Xylitol gum or toothpaste | Some caries evidence[22] | Low-quality trials |
| Lactoferrin plus lactoperoxidase tablets | One 12-week trial lowered gum inflammation scores at 60 mg a day[8] | Small, single trial; low dose failed |
| Dental exam and cleaning | Finds problems no supplement can | Cost and access |
| Synadentix | Contains some of the ingredients above | Doses hidden, no product trial |
The format question is covered on our Synadentix chewable tablet page.
How do you take Synadentix?
The label says to take 1 to 2 tablets a day after brushing, hold each in the mouth for 30 seconds, then swallow[2]. The vendor's other pages differ: the sales FAQ says to melt it under the tongue or chew it at night, and the contact FAQ says to chew one before bed[3]. We would follow the printed label.
Synadentix: final take
Synadentix may suit an adult with healthy gums who keeps brushing, flossing and seeing a dentist, wants to try oral-care ingredients in tablet form and accepts not knowing the doses. The ingredients are real; the evidence for this format and this product is not there yet.
Skip it if you have a milk, egg or almond allergy, take blood thinners, are pregnant or nursing, or have symptoms that need a dentist. Skip it too if you want a known lactoferrin dose, since the one positive tablet trial used 60 mg a day. If you buy, start with the smallest order, keep the box and packing slip, and note your delivery date for the 90-day window.
Frequently asked questions
What is in a Synadentix tablet?
Each tablet holds a 400 mg proprietary blend of guava fruit powder, microcrystalline hydroxyapatite, lactoferrin, lysozyme, lactoperoxidase, glucose oxidase, dextranase, amylase, amyloglucosidase and beta-glucanase. Xylitol, cellulose, magnesium stearate and flavoring are the other ingredients. No single dose is listed.
Is Synadentix safe for people with a milk or egg allergy?
Ask a clinician first. Lactoferrin and lactoperoxidase usually come from cow milk and lysozyme usually from egg white, and the Synadentix label does not state the source. Egg-allergic children have reacted to lysozyme in food.
How long does one bottle of Synadentix last?
One bottle holds 30 tablets. At 1 tablet a day it lasts 30 days; at the label maximum of 2 tablets a day it lasts 15 days. A 6-bottle order covers 6 months at 1 a day or 3 months at 2 a day.
Does Synadentix have an autoship subscription?
No. The vendor FAQ says Synadentix is a one-time charge with no autoship. After checkout you will see offers for extra bottles at $29 each, checked October 28, 2026. Decline any you did not plan to buy.
Can Synadentix replace brushing and flossing?
No. Synadentix is a supplement with no published product trial, and the best evidence for its ingredients comes from toothpaste used daily. Keep brushing, flossing and seeing a dentist, and get bleeding gums, pain or loose teeth checked.
Is xylitol in Synadentix a problem for pets?
Yes, for dogs. Xylitol is listed among the other ingredients, and it is toxic to dogs. Store the bottle where a dog cannot reach it, and contact a vet at once if a dog eats any tablets.
Does the FDA check Synadentix before it is sold?
No. FDA does not sign off on dietary supplements before sale. The vendor says Synadentix is made in an FDA registered facility, which is a registration, not a product approval. Its FAQ also calls the facility FDA accredited, which FDA does not do.
Do I pay return shipping on a Synadentix refund?
Yes. The refunds page says the buyer pays return postage. You email support with Refund Request in the subject, then mail all bottles, empty or not, with the packing slip within 90 days of delivery.
Can I take Synadentix with blood thinners?
Ask your doctor or pharmacist first. Synadentix contains xylitol, and one study found a xylitol drink raised platelet reactivity in healthy volunteers. Interactions with the tablet itself have not been studied.
Sources
- Synadentix sales page. Synadentix vendor, read October 28, 2026.
- References and Supplement Facts label. Synadentix vendor, read October 28, 2026.
- Contact us and FAQ. Synadentix vendor, read October 28, 2026.
- Refund policy. Synadentix vendor, read October 28, 2026.
- Shipping policy. Synadentix vendor, read October 28, 2026.
- Price configuration file. Synadentix vendor, read October 28, 2026.
- Terms and conditions. Synadentix vendor, read October 28, 2026.
- Lactoferrin and lactoperoxidase tablets and gingival health, 12-week randomized trial. PubMed, read October 28, 2026.
- Lactoferrin and lactoperoxidase tablets and oral bacteria in older adults. PubMed, read October 28, 2026.
- Hydroxyapatite oral care and caries, meta-analysis. PubMed, read October 28, 2026.
- Hydroxyapatite vs fluoride toothpaste in adults, 18-month randomized trial. PubMed, read October 28, 2026.
- Lysozyme toothpaste and recurrent mouth ulcers, randomized trial. PubMed, read October 28, 2026.
- Enzyme toothpaste in orthodontic patients, randomized trial. PubMed, read October 28, 2026.
- Enzymes against dental plaque, review. PubMed, read October 28, 2026.
- Guava fruit intake and experimental gingivitis, randomized trial. PubMed, read October 28, 2026.
- Guava leaf mouthrinse in gingivitis, clinical trial. PubMed, read October 28, 2026.
- Salivary amylase and oral bacteria. PubMed, read October 28, 2026.
- Multi-enzyme lozenge and dental plaque, randomized trial. PubMed, read October 28, 2026.
- Lysozyme in cheese and reactions in egg-allergic children. PubMed, read October 28, 2026.
- Safety evaluation of the food enzyme glucose oxidase. PubMed, read October 28, 2026.
- Xylitol, platelet reactivity and cardiovascular events. PubMed, read October 28, 2026.
- Xylitol-containing products for preventing dental caries, Cochrane review. PubMed, read October 28, 2026.
- openFDA food enforcement (recalls) search for Synadentix. US FDA, read October 28, 2026.
- openFDA CAERS adverse event search for Synadentix. US FDA, read October 28, 2026.
- BBB search for Synadentix. Better Business Bureau, read October 28, 2026.
- Wayback Machine capture index for thesynadentix.com. Internet Archive, read October 28, 2026.
This page is general information, not medical advice. Dietary supplements are not reviewed by the FDA for safety or effectiveness before they are sold and are not intended to diagnose, treat, cure or prevent any disease. Talk to your doctor before taking any supplement, especially if you are pregnant, nursing, take medication or have a health condition.