Onyx - prostate massager by Sinclair Intimacy Institute&re - review by Cindi025


Prostate massager by Sinclair Intimacy Institute

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Black Onyx: Versatile for Both Men and Women!

The Onyx is a great toy to add to your collection. It is great for a beginner who is new to anal, the girth isn't too thick, and the size isn't too overwhelming. It is shatterproof, easy to clean, and great for both p-spot and g-spot play. Give it a try, I think you will enjoy yourself very much!
Easy to clean, hypoallergenic, waterproof, rated 10 on safety.
Might not have enough girth for more advanced users.
Rating by reviewer:
extremely useful review


The Onyx is a prostate massager made by Sinclair Intimacy Institute. It is great for both solo play or partner play. Although it is considered a prostate massager, it also works great for the ladies as a g-spot massager. Being that I am female, this will mainly be used for g-spot play unless I have the boyfriend over and he is wanting some p-spot play. With this being a glass item, it is nonporous, latex-free, hypoallergenic, phthalates-free, and waterproof.

For anal p-spot play, I always recommend lube, especially if you are a beginner. If you plan on using this for both partners, I also recommend a condom if switching back and forth between vagina and anal with your partner. Another recommendation is to always use caution with glass since it can cause bruising or internal tearing.

For myself, I tend to use temperature play a lot with glass toys. It is very easy to heat or cool glass by simply placing in a bowl of hot water, or a bowl of cold water. You can also place in the refrigerator to cool it down quicker. Glass is always cool to the touch but will heat up to body temperature rather quickly when being used. Being waterproof, this toy can be used in a hot tub, pool, or shower.
  • Who / How / What
    [ ? ]
    Who might this product be best for? How is it best used? What are the best circumstances or situations for using this product?
    • Couples
    • Everyone
    • Temperature play
  • Where
    [ ? ]
    Where / what types of places can this product be used?
    • Anywhere
    • Campus/roommate living
    • Tub/shower/pool
  • Body / part areas
    [ ? ]
    What areas on the body can this product be used / what areas does it stimulate best?
    • Anal
    • G-spot
    • Kegels

Material / Texture

The Onyx is a glass toy made of black borosilicate glass. Borosilicate glass is also known as pyrex glass. This is the glass that is used for a lot of cookware. It is very firm, rigid, and does not have any flexibility at all. Borosilicate glass is rated a 10 on Eden safety chart, the highest you can get for safety.
It is odorless and tasteless. It is shatterproof and will not break like a normal piece of glass that you would drop on a hard floor. On occasion, you might find a small chip or crack, but you definitely will not have to worry about it shattering. Breaking is nearly impossible unless you plan on throwing it out a window thirty floors up.

This toy does have a good bit of texture due to the bulges and ridges on it. I definitely recommend lube, especially for anal use. This will help out when trying to get it inserted and on getting past the bulges. I would recommend this item for beginners as well as advanced users since it is very versatile for both men's and women's pleasure points.
    • Bumpy
    • No odor
    • Not porous at all

Design / Shape / Size

The Onyx is absolutely stunning to look at. It is black with a grey, etched leafy pattern. It measures around 6 inches if measured from top to bottom only. I find this to be an average size for a dildo. Measuring the actual curve shape of it, it is approximately 8 1/2 inches, 7 1/2 inches of which is insertable. This would be actually inserting all the way to the bulb shaped handle on the end of it. The circumference is around 2 1/2 inches at the tip and expands to around 3 3/4 inches at the widest part. The diameter is approximately 1 1/4 inches. I weighed it on my food scale and it weighed just under 7 oz. so it isn't very heavy at all.

I have included a comparison photo of the Cyclone, Golden G. and the Onyx. I found the Onyx is just slightly smaller than the other two items shown.

    • Beginner
    • Partner play
    • Whimsical / artistic


I found I just loved this toy. It is very versatile, being that it can be used to stimulate both male and female pleasure points. The size was not intimidating at all. I honestly was afraid when I saw 8 1/2 inches that it would be huge, and I was pleasantly surprised when I received it and it was so small. The girth on this toy wasn't thick at all, so it was fairly simple for me to insert without lube. I also love that glass is so easy to care for. As far as the boyfriend and anal, well, that is another story.

When I showed this toy to the boyfriend, he definitely was a little scared since he had only done anal a few times in his life. Luckily, to my surprise, he did allow me to try it on him. He did say when finished that he enjoyed it very much and that he definitely would like to use it again in the near future.

This product is not harness-compatible and does not have a suction cup.
    • Discreet sound
    • Easy to use
    • Not very discreet

Care and Maintenance

Caring for the Onyx is very simple. Being that it is a glass item, it can be cleaned like most any item with soap and water. It can be placed in a dishwasher on the top shelf or sterilized in a pot of boiling water for three minutes. It can also be washed in 10% bleach and water, though I myself do not like the smell so I will not do it that way.

Storing is also very simple. I would recommend placing this in a padded toy pouch if you have one available. If not, you can of course purchase one here at Edenfantasys for around $10. If you choose not to use a toy pouch, you could also wrap in bubble wrap or wrap with a hand towel or wash cloth and put it in a drawer or somewhere else safe. Of course, you can also keep it in the packaging it came in as well. The packaging will definitely keep it safe and away from any lint or dust.

Any lubes can be used with glass items. Take your pick; whether it be silicone-based, water-based, or oil-based, you will be fine.

    • Easy to clean
    • Easy to store


The Onyx comes in a white box. On the side of the box is a picture of the Onyx. On the bottom is the care instructions in two languages and also the company information. On the front of the box is the ONYX logo and the product description, again in two languages. Also looking at the box from the front, there is a cutout in the box where the Onyx can show through the plastic holder. On the back is some detailed information about the Onyx. Opening the box is very simple. Once you open it, you will see the Onyx in a plastic holder with a curved shaped cutout to hold the product nicely.

This item did not come with any instructions or paperwork. I honestly don't think it is necessary though for this product. It also did not come with a toy pouch like many glass items do. No extras were included; no lube, toy wipes, or anything else.

    • Not discreet

Personal comments

As for myself, I loved this toy for g-spot play. Speaking for the boyfriend he enjoyed it as well. I did find that with him being a beginner to anal, it took some time to get it inserted, but once that happened he was definitely enjoying himself. I definitely recommend lube if anal isn't something regular that you enjoy. I wasn't able to insert all the way, but I would say I probably got it in about 5 or 6 inches, so not bad at all for a beginner. He did say the raised bulges added a good bit of texture as well to the play. I definitely look forward to using this toy again on him and hopefully making him a regular to anal play. Hopefully one day he will be to take it all.


All I can say are good things about this item. It is very pretty to look at. The size isn't too overwhelming for beginners, and the girth isn't too thick at all. Temperature play is just great and cleaning is very easy. Being rated a 10, safety shouldn't be a concern at all.
Follow-up commentary
The onyx has become a favorite for my boyfriend to use. Although I myself do not use it he just loves it. With a little lube it definitely does its job well. This is not a large toy at all so beginners shouldn't be intimidated at all. I recommend all users to give it a try!
This product was provided free of charge to the reviewer. This review is in compliance with the FTC guidelines.
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This review was edited by
  • Sir Sir
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  • Sir
    Thank you for the extensive review!
  • britanny0620
    Thanks for the review
  • XxFallenAngelxX
    Great job, Cindi!
  • r00ster
    Thanks for the review
  • Boyfriend
    thank you
  • AnnieMouse
  • Cindi025
    thanks everyone!
  • SecretKinksters
    Nice review, thanks for sharing!
  • Rossie
    Great review, thank you for sharing your beautiful toy with us.
  • *Camoprincess*
    Great job this piece has me wondering may add it to my list
  • bayosgirl
    Great shape. EU review.
  • The Vixen
    Great review and thanks for adding all the nice pics Thank you!
  • Falsepast
    Thanks for the pics
  • PeaceToTheMiddleEast
    Great review, thanks for sharing!
  • GONE!
    Great review and photos!
  • Princess-Kayla ?
    Great review! This toy looks wonderful!
  • 1001 Pleasures
    Such a nice comprehensive review. I've had my eye on this for a bit, but so far Eden isn't selling it.
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